Universal Dissociated Anesthesia due to Bilateral Brain-Stem Infarcts Nagagopal Venna, MD, MRCP(I), MRCP(UK), Thomas D. Sabin, MD \s=b\ A 59-year-old man had loss of pinprick and temperature sensation over his head, face, neck, trunk, and all extremities while light touch, vibration, joint position sense, and deep pain were pre- served. This was the cumulative result of infarctions in the territories of the right superior cerebellar and left posterior inferior cerebellar arteries that occurred three years apart. To our knowledge, a syndrome of bilateral discrete interruption of spinothalamic tracts and of the spinal tracts of the trigeminal system in the brain stem has not been reported. Dissociated sensory loss enveloping the entire body accompanied by truncal and limb ataxia without weakness demonstrated a striking clinical picture. The preservation of deep somatic and visceral pain when cutaneous pain sensation was lost was another notable feature. We review the causes of widespread dissociated sensory loss and discuss the implications of the dissociation of deep from superficial pain. (Arch Neurol 1985;42:918-922) Tnfarction in the territory of the pos¬ terior inferior cerebellar artery (PICA) produces the unique and wellrecognized Wallenberg's lateral med¬ ullary syndrome. Infarction in the pons and cerebellum due to occlusion of the superior cerebellar artery (SCA) is much less common. We had the opportunity to observe a patient who suffered an SCA distribution Accepted for publication July 3, 1984. From the Department of Neurology, Boston University School of Medicine, and the Neurological Unit, Boston City Hospital. Reprint requests to Neurological Unit, Boston City Hospital, 818 Harrison Ave, Boston, MA 02118 (Dr Venna). infarction followed three years later by contralateral PICA syndrome. We paid particular attention to the unusual sensory abnormalities that accrued from these strategically placed lesions. REPORT OF A CASE At age 52, the patient experienced new onset of intermittent headaches spreading from the back of the neck to the forehead. Six months later, in June 1976, the patient by a brief loss of consciousness followed by dizziness and imbalance. Phys¬ ical examination showed markedly slurred speech, left central facial weakness, tran¬ sient, mild left hemiparesis, and severe, persistent ataxia of the right upper and lower extremities. This picture was consis¬ tent with infarction in the distribution of right SCA. There was no evidence of diabe¬ tes mellitus or hypertension, but occult rheumatic mitral stenosis without atrial fibrillation was detected. Warfarin sodium (Coumadin) therapy was started on the assumption that the brain-stem infarction was secondary to cardiogenic embolism. In January 1979, the patient experienced an abrupt onset of syncope, headache, diz¬ ziness, slurred speech, and unsteadiness. Physical examination demonstrated a nor¬ mal mental state, skew deviation of the eyes, constant rotatory nystagmus that became left-beating on left gaze, and left Horner's syndrome. Sensation to pinprick and temperature was diminished on the left half of the face and movement of the left half of the soft palate was decreased. There was ataxia of the left upper and lower extremities but no comment was made about the sensation on the body. Distressing hiccups that persisted for two weeks completed the clinical picture of left lateral medullary infarction. Two weeks later dense macular-sparing right homonymous hemianopia due to infarction of the left calcarine cortex developed. A fourvessel angiogram showed nearly complete occlusion of the vertebral arteries at the C-l to C-2 level. was struck A year later, when the patient was seen for myoclonic jerks of the upper extremi¬ ties and abrupt momentary lapses of pos¬ ture, cuts and cigarette burns were observed on the fingers of which he was unaware. Two years after the last stroke, distressing burning and stinging sensa¬ tions appeared over the face, extremities, and trunk and the patient had become deeply depressed. Both the mood and dysesthesias improved gradually on tricy¬ clic antidepressant drug therapy. Examination in June 1982 This article is based chiefly on this examination six years after the first stroke. The patient was depressed but his mental state was otherwise normal. Right homonymous hemianopia, left-sided Hom¬ er's syndrome, and constant rotatory nys¬ tagmus intensified by left gaze and vari¬ ably altered by head position, bilateral depression of corneal reflex, markedly dysarthric speech, and decreased move¬ ments of the left side of the palate were noted. Ataxia of the cerebellar type was pronounced in all extremities along with postural tremor of the upper extremities. The knee reflexes were pendular and the left plantar reflex was upgoing. His gait was wide-based and unsteady. Sensory Examination Figures 1 and 2 showed a marked decrease in the sensation of pinprick over the head and face including the external ear and on the neck, trunk, extremities, perineal region, scrotum, and penis. Pin¬ prick was markedly diminished over the mucous membranes of the lips, gums, cheeks, tongue, and palate, while taste and smell sensations were normal. There was marked decrease in appreciation of hot and cold as tested by test tubes of hot water and ice water in the same distribution, except over the paraspinal area of the lower trunk. Temporal summation was demonstrated with repeated pinpricks over all the extremities and application of cold to the legs caused a disagreeable sensation. Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/22/2015 Fig 1. Sensory examination showing marked decrease in pinprick sensation (slanted lines) over head, face, external ear, neck, trunk, extremities, perineal region, scrotum, and penis. — Deep pain was tested in the lower extrem¬ ities by squeezing the Achilles tendons and calf muscles, pinching full thickness of the skin of the thighs, deep pressure on the pretibial regions, and passive hyperextension of the toes. All these maneuvers pro¬ voked pain described by the patient and readily observed in his facial expression. Pressure over the anterior superior iliac spines, squeezing the testicles, and pres¬ sure over the sternum also easily elicited pain. In the upper extremities, pain was produced by pinching the axillary fold, squeezing the forearm and upper arm mus¬ cles, and passive hyperextension of the fingers. Pressure over the supraorbital region, frontal and maxillary sinuses, and the stylomastoid processes was equally painful. Immersion of upper limbs to the elbows in ice water for two minutes failed to produce the deep aching pain normally felt in the shoulder area within 20 s. Light touch, vibration, and passive movements of joints were normal over the entire body. A month after this examination severe and typical left pleuritic chest pain due to left upper lobe pneumonia developed in the patient. A short time later he fell and sustained a contusion of his right thigh and hip and in another fall, contusion of the foot and toes. Both episodes caused normal deep pain for over two weeks. At the time of foot contusion, moving the bruised toes was markedly painful, while pinprick over the same toes was not felt. Laboratory Tests computed tomographic (CT) scan (Fig 3, left and right) of the brain in June 1982 demonstrated a right cerebellar low density consistent with right SCA territo¬ A ry infarction. In addition, left calcarine Fig 2. Sensory examination showing marked decrease in thermal sensation (dots) over most of body except paraspinal area of lower trunk. — Fig 3.—Computed tomographic (CT) scan of brain in June 1982 showing infarction in territory of right superior cerebellar artery. Left, Low density in right half of cerebellar vermis. Right, Low density in superior aspect of right cerebellar hemisphere. In both CT scans, low-density area abuts on fourth ventricle. and left posterior parietal infarctions were seen. COMMENT The first stroke is consistent with infarction in areas of the pons and cerebellum supplied by the SCA.1-' The structures usually affected by SCA occlusion are in the lateral superior segment of the pons and include the lateral spinothalamic tract, spinal tract of the fifth cranial nerve, the descending sympathetic fibers, the superior and middle cerebellar pedun¬ cles, and the superior surface of the cerebellum and dentate nucleus (Pig 4). The second stroke is typical of Wallenberg's lateral medullary syn¬ drome (Fig 5) resulting from infarc¬ tion in the distribution of PICA though the occlusion is usually in the vertebral artery at the mouth of the PICA.45 The infarction in the lateral corner of the medulla affects the descending tract and nucleus of the fifth cranial nerve, lateral spinotha¬ lamic tract, the descending sympa¬ thetic chain, the nucleus ambiguus of the vagus nerve, and vestibular nuclei, Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/22/2015 chief Superior Cerebellar Peduncle Cerebellum Lateral Lemniscus Medial Longitudinal Fasciculus Lateral Spinothalamic Tract Central Tegmental Bundle Medial Lemniscus Pontine Nuclei and Pontocerebellar Fibers nociceptive pathways of the extremities, trunk, head, and neck have been discretely interrupted, while principle proprioceptive path¬ ways in the medial lemnisci and the corticospinal motor system were unaffected. The intactness of sensa¬ tion over the trunk, as depicted in Fig 2, is difficult to explain on an anatom¬ ic basis because the trunk fibers are located between the cervical and sacral fibers in the lateral spinotha¬ lamic tract laminations of the brain stem. It may be that recovery of ther¬ mal sensation had begun in this area. Corticospinal Tract Fig 4.—Outlines structures usually affected by superior cerebellar artery occlusion resulting in lateral superior pontine infarction. Vestibular Nucleus Inferior Cerebellar Peduncle Descending Nucleus and Tract Nucleus Solitarius, Fifth Cranial Nerve Twelfth Cranial Nerve Nucleus Medial Longitudinal Fasciculus Nucleus Ambiguus Cerebellum Medial Lemniscus Descending Sympathetic Tract Dorsal Spinocerebellar Tract Spinothalamic Tract Ventral Spinocerebellar Tract Inferior Olive Pyramid Stroke pattern typical of Wallenberg's lateral medullary syndrome. Fig 5. — as well as the inferior cerebellar pe¬ duncle and the inferior surface of the cerebellum. In addition, the patient had an infarction in the left calcarine cortex and a left parietal infarction without evidence of aphasia or Gerstmann's syndrome. The basis of these lesions seemed to be vertebrobasilar atherosclerosis-thrombosis and cardiogenic embolism due to mitral ste¬ nosis. Sensory Abnormalities The outstanding feature in this patient is the cutaneous analgesia to pinprick and temperature stimuli that enveloped the body from the vertex to the toes and analgesia of the buccolingual mucous membranes. In contrast, light touch, vibration, and joint posi¬ tion sense were exquisitely preserved. This picture of total body dissociated sensory loss (loss of pinprick and tem¬ perature with preservation of light touch and proprioception) without weakness due to brain-stem lesions has not been previously described to our knowledge. The strategic location and unusual combination of the brain¬ stem infarcts led to the appearance of this remarkable syndrome. Based on clinicopathologic features of SCA and PICA infarctions, we conclude that the sensory abnormality resulted from the interruption of the lateral spinothalamic tracts and the spinal tracts of the trigeminal systems of both sides of the brain stem. Thus the The question of asymbolia to pain67 is addressed here because the patient was found to have an infarction in the posterior left parietal lobe on CT scan. Such a lesion in the vicinity of the left supramarginal and angular gyri may cause this rare syndrome of striking absence of the normal defensive and facial reactions to painful stimuli applied to either side of the body. Patients may inflict severe injury on themselves accidentally or deliberate¬ ly. Sometimes this abnormal response extends to other threatening stimuli such as loud noises or sudden flashes of light. However, the patients can distinguish pinprick and temperature and perceive touch and propriocep¬ tion. In most instances there are neighborhood signs of aphasia, frag¬ ments of Gerstmann's syndrome, apraxia, and extinction of double simultaneous stimulation with touch. Therefore, our patient's sensory abnormalities are not consistent with asymbolia to pain. The possibility of coexisting cere¬ bral hemispheric lesions causing bilateral dissociated sensory loss must also be considered. Cerebral lesions near the somatosensory cortex can produce impairment of pain and temperature sensibility in the contralateral half of the body, but this is usually evanescent. However, Biemond8 described unusual cases of enduring impairment of pinprick and thermal sensation on the contralater¬ al half of the body including the face and trunk with preservation of light touch, position, and vibration sense and stereognosis but the state of deep pain was not described. The lesions were located in or under the parietal operculum. This chronic dissociated hemianesthesia is the reverse of the usual pattern of suprathalamic lesions where proprioception, light touch, deep pain, and stereognosis are severely decreased while pain and temperature are little affected. Biemond8 postulated that this syndrome Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/22/2015 of dissociated anesthesia may be due to the involvement of the secondary somatosensory area located in the parietal operculum. In our patient there is only one parietal lesion and it is retrosylvian and thus unlikely to cause the sensory disturbance. The syndrome of universal dissoci¬ ated sensory loss without paralysis observed in our patient is seen in only a few other rare diseases. In congeni¬ tal indifference to pain,910 the patients, from early childhood, show an astonishing lack of normal reflex and affective and vegetative re¬ sponses to superficial and deep pain. They sustain repeated cuts, burns, fractures, and visceral catastrophies without pain. However, neurological examination demonstrates that they can discriminate pinprick, heat, touch, and joint movement, and pres¬ sure at a normal threshold and tendon reflexes are normal. Thus the hall¬ mark of the disease is the altered reaction to superficial and deep pain. No pathologic substrate has been found, but a recent study indicates that the endogenous opiate system 12 may be hyperactive." Congenital insensitivity to pain with anhydrosis13 is a rare syndrome characterized by severe, universal impairment of superficial and deep somatic and visceral pain and temper¬ ature sensibility while touch, proprio¬ ception, and tendon reflexes are intact. Sweating is absent and the patients are mildly mentally retarded. Absence of the small neurons of dor¬ sal root ganglia and Lissauer's tracts of the spinal cord, and attenuation of the descending tract of trigeminal nerves has been observed on postmor¬ tem examination. Thus there is selec¬ tive lack of development of the princi¬ ple pain-conducting structure of nerve roots and spinal cord. Certain types of polyneuropathies due to amyloidosis14 and a rare form of diabetic polyneuropathy15 are known to cause dissociated anesthe¬ sia, but the stocking-glove pattern of the distribution of sensory change is distinctive. Kocen et al16 described a patient with the Tangier disease (alipoprotein deficiency) who was seen with dissociated sensory loss over the head, face, neck, upper extremities, trunk, and most of the lower extremi¬ ties except the lower parts of the legs and feet, which was due to peripheral neuropathy. Enlarged orange-colored tonsils and deficiency of plasma alipoprotein are the hallmarks of this disease. An occasional case of syringomyelia extending into the medulla and the thoracic and lumbar spinal cord can cause extensive dissociated anesthesia by interrupting the decussating nociceptive fibers and the spinothalamic tracts,17 but segmental amyotrophy and segmental loss of tendon reflexes distinguish this disorder. Dissociated anesthesia of all limbs and trunk occur in anterior spinal artery occlu¬ sion with infarction of the high cervi¬ cal spinal cord,18 but the face is not affected and quadriplegia is present. Dissociation of Superficial and Deep Pain A remarkable feature in our patient is the intactness of deep somatic pain sensibility with marked impairment of superficial pain (dissociated anal¬ gesia). This is demonstrated by nor¬ mal pain elicited by stimuli applied to the tendons, muscles, and periosteum and by the patient's experience of pain from trauma to soft tissues of the thigh and foot. Preservation of nor¬ mal pain elicited by testicular com¬ pression and the experience of pain from the pleural inflammation indi¬ cates intact visceral pain. Thus, this patient demonstrates that superficial pain loss can be dissociated from deep somatic and visceral pain at some stage. Unfortunately, the deep pain perception was not tested until six years after the first stroke, so that we cannot determine whether both deep and superficial forms of pain were initially lost with preferential recov¬ ery of deep pain or whether these modalities of pain were differentially affected from the outset. The information on the alterations of deep pain resulting from lesions of central pathways is scanty because it has not been examined systemically even when the patient's chief symp¬ tom is sensory loss. To our knowledge, there are no cases of cerebral hemi¬ spheric lesions where deep pain has been specifically probed. Only slightly more information is recorded in rela¬ tion to lesions of the medulla. Soffin et al19 described the fascinating evolu¬ tion of patterns of dissociated sensory loss from the PICA syndrome in sev¬ eral patients, but the fate of deep pain is not recorded. Nathan20 alluded to two patients with PICA syndrome in whom deep painful stimuli to the analgesic side were referred to the normal side of the body. Patients who underwent lateral medullary tractotomy offer another opportunity to examine this situation. In this proce¬ dure, spinothalamic tracts in the retro-olivary segment of the medulla are cut to obtain relief from intracta¬ ble pain in the upper extremity, shoul- der, upper thorax, and neck. In most cases, deep pain is abolished along with cutaneous pain sensibility in the contralateral body to the neck but the original pain returns weeks, months, or a few years later. It is not known if superficial and deep pain sensibility recover hand in hand or differentially. White and Sweet21 refer to a patient where contralateral testicular pain was elicited even though there was complete cutaneous analgesia to the chin. To our knowledge, there are no reported cases of bilateral lateral medullary lesions, spontaneous or surgical. Deep pain has been more extensive¬ ly studied in patients who underwent anterolateral cordotomy for intracta¬ ble pain, aimed at interrupting the lateral spinothalamic fibers. Most lesions are made in the thoracic spinal cord but some lesions are in the cervi¬ cal spinal cord. The results are similar to medullary tractotomies in that cutaneous analgesia occurs along with abolition of deep pain for which the operation is indicated, but after weeks to years, original pain returns. Again the relationship between disappear¬ ing cutaneous analgesia and returning deep pain has not been recorded criti¬ cally. Despite these general findings, White and Sweet21 and Hyndman and Wolkin22 observed that some of their patients with unilateral anterolateral cordotomies experienced deep pain in the parts of the body with cutaneous analgesia on compression of the testi¬ cle, squeezing of Achilles tendon, and bone pressure, and one felt the pain of a fractured ankle, another felt pain from contusion of the thigh. Nathan20 noted that in patients who underwent unilateral cordotomy deep pain stimu¬ li to the analgesic parts were referred to the normally innervated contralat¬ eral side or to the ipsilateral side above the sensory level. Nathan20 also described a patient with destruction of both anterior quadrants of the spi¬ nal cord as a result of anterior spinal artery infarction in whom deep pain below the level of dissociated sensory loss was referred to the body above the sensory level. Thus, there is some evidence that medullary and spinal cord lesions in the vicinity of the lateral spinothalamic tracts can lead to a situation where cutaneous pain is abolished but deep pain is still felt either normally or distorted and referred to normally innervated parts of the body. Little is known of the pathways in the CNS by which pain from deep somatic tissues and viscera is trans¬ mitted. It is generally stated that this Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/22/2015 information travels with or in the spinothalamic system.23 The retention of deep pain while cutaneous pain is lost, as in our patient, after bilateral lesions of spinothalamic tracts and spinal tracts of the trigeminal com¬ plex lends itself to several interpreta¬ tions of its mechanism: it may be that all modalities of pain are, under nor¬ mal circumstances, conveyed by spi¬ nothalamic tracts, but after injury deep pain recovers better and sooner than cutaneous pain. Alternatively, deep pain may be transmitted by tracts that are separate but in prox¬ imity to spinothalamic fibers such as spinotectal and spinoreticular tracts.24 Tracts in the posterior half of the spinal cord may be involved in nociception either normally or when acti¬ vated by interruption of spinothal¬ amic tracts by disease or surgery. For instance, the dorsal intercornual tract, a system of polysynaptic con¬ nections ascending in the gray matter of dorsal horns, has been proposed as potential pathway.24 Denny-Brown25 proposed a similar pathway of pain transmission in a posterior spinal commissure interconnecting the sub¬ stantia gelatinosa and spinocervical tracts of the two sides to explain the extraordinary results of cordotomies in the monkey. He showed that pain that was abolished by hemisection of the spinal cord returned after bilater¬ a al destruction of the ventral cord! Careful evaluation of the state of deep somatic and visceral pain is indi- cated in patients with disturbances of pain perception from CNS as well as peripheral nervous system lesions. This, we believe, will broaden the clin¬ ical spectrum in which deep pain is affected and will throw light on its mechanisms. References 1. Luhan JA, Pollack SL: Occlusion of the superior cerebellar artery. Neurology 1953;3:77\x=req-\ 89. 2. Freeman W, Jaffe D: Occlusion of the supe- rior cerebellar artery: Report of case with necropsy. Arch Neurol 1941;46:115-126. 3. Gillian LA: The correlations of the blood supply to the human brain stem with clinical brain-stem lesions. J Neuropathol Exp Neurol 1964;23:78-108. 4. Currier RD, Giles CL, DeJong RN: Some comments on Wallenberg's lateral medullary syndrome. Neurology 1961;11:778-791. 5. Fisher CM, Karnes WE, Kubik CS: Lateral medullary infarction: The pattern of vascular occlusion. J Neuropathol Exp Neurol 1961;20:323\x=req-\ 379. 6. Schilder P, Stengel E: Asymbolia for pain. Arch Neurol 1931;25:598-600. 7. Hecaen H, de Ajuriaguerra J: Asymbolie a la douleur, \l=e'\tudeanatomodinique. Rev Neurol 1950;83:300-302. 8. Biemond A: The conduction of pain above the level of the thalamus opticus. Arch Neurol 1956;75:231-244. 9. Arbuse DI, Cantor MB, Barenberg PA: Congenital indifference to pain. J Pediatr 1949; 35:221-226. 10. Baxter DW, Olszewski J: Congenital universal insensitivity to pain. Brain 1960;83:381\x=req-\ 393. 11. Dehen H, Willer JC, Prier S, et al: Congenital insensitivity to pain and the "morphine-like" analgesic system. Pain 1978;5:351-358. 12. Hishashi Y: Congenital insensitivity to pain and naloxone. Lancet 1978;2:502-521. 13. Swanson AG: Congenital insensitivity to pain with anhidrosis. Arch Neurol 1963;8:299\x=req-\ 306. 14. Andrade C: A peculiar form of peripheral neuropathy. Brain 1952;75:408-427. 15. Brown MJ, Marton JR, Asbury AK: Painful diabetic neuropathy: A morphometric study. Arch Neurol 1976;33:164-171. 16. Kocen RS, Lloyd JK, Lascelles PT, et al: Familial alpha-lipoprotein deficiency (Tangier disease) with neurological abnormalities. Lancet 1967;1:1341-1345. 17. Adams RD, Victor M: Diseases of the spinal cord, in Principles of Neurology, ed 2. New York, McGraw-Hill Book Co, 1981, chap 35, p 643. 18. Moossy J: Vascular diseases of the spinal cord, in Baker AB, Baker LH (eds): Clinical Neurology. New York, Harper & Row Publishers Inc, 1983, vol 3, chap 46, p 13. 19. Soffin G, Feldman M, Bender MB: Altera- tions of sensory levels in vascular lesions of lateral medulla. Arch Neurol 1968;18:178-190. 20. Nathan PW: Reference of sensation at the spinal level. J Neurol Neurosurg Psychiatry 1956;19:88-100. 21. White JC, Sweet WH: Spinothalamic tractotomy: Comparison of the results of tractotomy at different levels of spinal cord and brain stem, in Pain and the Neurosurgeon. Springfield, Ill, Charles C Thomas Publisher, 1969, chap 15, pp 689-690. 22. Hyndman OR, Wolkin J: Anterior chordotomy. Arch Neurol 1943;50:129-148. 23. Mountcastle VB: Pain and temperature sensibilities, in Mountcastle VB (ed): Medical Physiology. St Louis, CV Mosby Co, 1974, vol 1, chap 11, p 369. 24. Kerr FWL, Fukushima T: New observation on the nocioceptive pathways in the central nervous system, in Bonica JJ (ed): Pain. New York, Raven Press, 1980, pp 47-61. 25. Denny-Brown D: The enigma of crossed sensory loss with cord hemisection, in Bonica JJ, Leibeskin JC, Albe-Fessard DG (eds): Advances in Pain Research and Therapy. New York, Raven Press, 1979, vol 3, pp 889-895. Isolated Cerebral Phycomycosis Presenting as Focal Encephalitis Danny F. Watson, MD; Barney J. Stern, MD; Michael L. Levin, MD; Deepa Dutta, MD \s=b\ A patient with features of a focal encephalitis was found to have isolated cerebral phycomycosis. No risk factors for phycomycosis were present, and the diagnosis was made by brain biopsy. (Arch Neurol 1985;42:922-923) Accepted for publication Nov 8, 1984. From the Department of Neurology, The Johns Hopkins Hospital, Baltimore (Drs Watson and Stern), and the Departments of Medicine (Drs Stern and Levin) and Pathology (Dr Dutta), Sinai Hospital of Baltimore. Reprint requests to Division of Neurology, Sinai Hospital of Baltimore, Baltimore, MD 21215 (Dr Stern). T^he patient with fever, confusion, and focal cerebral signs requires urgent diagnosis and treatment. When the course of the illness, results of cerebrospinal fluid (CSF) examina¬ tion, and computed tomographic (CT) scans are compatible with a focal encephalitis, brain biopsy must be considered to investigate the possibil¬ ity of herpes simplex encephalitis (HSE). We report a case in which brain biopsy for suspected HSE estab¬ lished the diagnosis of phycomycosis confined to the central nervous sys- tern (CNS) in a patient without known risk factors. REPORT OF A CASE A 26-year-old woman developed fever, headache, nausea, vomiting, and lethargy that grew steadily worse. On the fourth day of her illness, she complained of diplo¬ pia. The next day, her family noted mild difficulty with her speech. On the sixth day, she was brought to the emergency room because of worsening confusion and inability to speak. Her medical history was notable only for asthma and allergic rhini¬ tis. Her medications were oral contracep- Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/22/2015