EUROPEAN JOURNAL OF EMERGENCY MEDICINE, 1996, 3, 194-198 CASE REPORT A rare case of diplopia: medial inferior pontine syndrome or Foville’s syndrome I. HUBLOUE™, S. LAUREYS? and A. MICHOTTE? 1Emergency Department and *Neurology Department, University Hospital of the Free University of Brussels (AZ-VUB), 101 Laarbeeklaan, 1090 Brussels, Belgium A case of medial inferior pontine syndrome or Foville’s syndrome is described. The patient presented to the emergency department with an acute history of slurred speech, vertigo and diplopia as major complaints. He also mentioned the appearance of weakness and numbness in his left leg. The physical examination revealed a crossed neurological deficit (ipsilateral cranial nerve deficit with contralateral motor weakness) which is typical for posterior circulation stroke in the brainstem territory. In our patient the lesion was located in the right medial inferior pontine region. All the symptoms and signs disappeared within 24 hours confirming the importance of a detailed physical and neurological examination of each patient presenting at the emergency department with a neurological deficit. Keywords: crossed paralysis; medial inferior pontine syndrome; Foville’s syndrome; symptoms and signs CASE REPORT A 74-year-old retired musician was admitted to the emergency department with a history of slur- red speech, vertigo and diplopia. He also men- tioned the appearance of weakness and numbness in his left leg. The patient’s wife noticed the pres- ence of strabismus as a result of impaired motility of the right eye. All these symptoms suddenly occurred 2 h before admission. Medical history consisted of depression, an acute myocardial infarction, a cerebellar stroke a few years earlier and multiple surgical interventions (bilateral inguinal hernia, left meniscectomy, par- tial gastrectomy after peptic ulcer, peritonitis of unknown origin, removal of vocal cord polyps). He also wore a hearing-aid for bilateral hypo- acousis due to otosclerosis. He stopped smoking cigarettes 9 years previously; the tobacco- consumption at that time was estimated at 50 packyears. There was no abuse of alcohol. His daily medication consisted of amitriptylin 75 mg once a day and bromazepam 6 mg before sleep- ing. *To whom correspondence should be addressed 0969-9546 © 1996 Chapman & Hall General physical examination showed no abnor- mal findings. The blood pressure was 130/80 mmHg, the heart rate 80 beats/min and regular. Auscultation of the heart and lungs was normal, as was the examination of the abdomen. A detailed neurological examination revealed a normal mental status, adduction and abduction paresis of the right eye, adduction paresis of the left eye and a horizontal nystagmus of the left eye on lateral gaze (abduction). There was a weakness of the right half of the face with a marked asym- metry of the nasolabial folds. Furthermore the patient presented a mild paresis of the left arm and leg and an impaired tactile and proprio- ceptive sense over the left half of the body with preserved pain and temperature perception. The finger—nose testing was less disturbed than the heel-to-shin testing on the left side of the body. Performing the Romberg-test the patient had dif- ficulty in holding his position with open as well as with closed eyes. He tended to fall over to the right. Both deep tendon and regressive reflexes were symmetric and brisk. Snout, root and grasp reflexes were absent. Based on the medical history and the findings on the clinical examination the diagnosis of posterior circulation stroke, more specific right medial A RARE CASE OF DIPLOPIA ER SEMEN. OM>Dr. HUE La UE Fig. 1. Computed tomography scan of the brain (at the level of the pons) performed 6 h after admis- sion. inferior pontine syndrome or Foville’s syndrome was forwarded. ECG, chest X-ray and blood analysis performed at the emergency department were normal. A computed tomography (CT) scan of the brain with and without contrast performed 6 h after admission revealed cortical atrophy but no other abnormalities (Fig. 1). The patient was admitted to the neurology ward for a detailed neurological work-up. Aspirin 160 mg once a day was added to his daily medication. The day after his admission the neurological examination was completely normal. A magnetic resonance image (MRI) of the brain confirmed the presence of cortical atrophy but no other abnor- mal findings were evidenced (Fig. 2). Electroen- cephalography (EEG) and echocardiography were normal. An isotopic brain perfusion-scintigraphy with acetazolamide _ stress-testing showed a decreased vasodilatory reserve in the territory of the vertebrobasilar circulation. On carotid duplex scanning normal flow-velocities in both arteries and no high-grade stenoses were found. An angiography of the aortic cross, carotid and verte- bral arteries, performed to complete the neurovas- cular evaluation, demonstrated in contrast with the duplex scanning an asymmetric concentric 195 Fig. 2. Magnetic resonance image of the brain (at the level of the pons) performed the day after admission. stenosis of 75% at the level of the right carotid artery bifurcation and also a hypoplastic right vertebral artery with multiple stenotic lesions. The asymptomatic character of this 75% stenosis made it no direct indication for carotid endar- terectomy. After 5 days the patient was dismissed from the hospital. On neurological examination a few weeks later at the outpatient clinic no abnormal findings could be evidenced. His daily medica- tion consisted of aspirin 160 mg once a day, ami- triptylin 75 mg once a day and bromazepam 6 mg before sleeping. DISCUSSION Neurological disorders are among the most com- mon in the emergency department (ED). The approach of the patient with a neurological deficit can be considered a challenging test of the problem-solving ability of the emergency physi- cian. Although a large battery of diagnostic tests is available for each problem daily seen in the ED, the diagnosis of neurological problems is mainly based on medical history and on detailed neuro- logical examination. The physician must integrate EUROPEAN JOURNAL OF EMERGENCY MEDICINE (1996) 3(3) 196 HUBLOUE, LAUREYS and MICHOTTE Table 1. The lesion sites and associated clinical syndromes in the four crossed paralyses Syndrome Lesion site Clinical syndrome Millard-Gubler Caudal ventral pons: Facial palsy (1856) cranial nerve VIi Contralateral hemiparesis Corticospinal tract Weber (1863) Cerebral peduncle: cranial nerve Ill Corticospinal tract Raymond-Cestan (1903) Corticospinal tract Medial lemniscus Spinothalamic tract Rostral tegmental pons: medial longitudinal fasciculus Oculomotor palsy Contralateral hemiparesis Internuclear ophthalmoplegia Contralateral dysesthesias Cerebellar signs Hemiparesis Superior/middie cerebellar peduncle Foville (1858) Caudal tegmental pons: cranial nerve VII, VI Paramedian pontine reticular formation Corticospinal tract physical findings with brain anatomy and func- tion to determine the anatomic location of the lesion. His second goal will be the determination of the possible vessels that may be involved in case of stroke syndromes. One should keep in mind that physical findings often follow very classical patterns that can assist the emergency physician when locating the lesion. As an ex- ample of the importance of a carefully per- formed neurological examination on admission, we described this case of medial inferior pontine syndrome or Foville’s syndrome. The four original brainstem syndromes described in the 19th century by Millard, Gubler, Weber, Foville, Raymond and Cestan contributed largely to the understanding of the neuro-anatomy of the brain stem (Foville, 1858; Larmande, 1985; Silver- man et al., 1995). These crossed paralyses featured cranial nerve deficits contralateral to limb weak- ness (Wall, 1991; Simon and Ho, 1992; Silverman et al., 1995; Henry, 1996). In the case of the Millard-Gubler syndrome it consists of facial palsy and contralateral hemiparesis (Wall, 1991; Silverman et al., 1995). The Weber syndrome is characterized by oculomotor palsy and contra- lateral hemiparesis (Wall, 1991; Silverman et al., 1995). The Raymond-Cestan syndrome is known by the presence of an internuclear ophthalmo- plegia and contralateral hemiparesis (Wall, 1991; Silverman et al., 1995). In 1858 Achille Louis Foville (1799-1878) published a case of a 43-year- old commissionaire suffering from a total left facial paralysis, an inability to look leftward and a right-sided hemiparesis (Foville, 1858). The Foville’s syndrome is characterized by a peri- pheral type of facial palsy, conjugate gaze paraly- EUROPEAN JOURNAL OF EMERGENCY MEDICINE (1996) 3(3) Facial paralysis Conjugate gaze paralysis Contralateral hemiparesis sis and contralateral hemiparesis (Foville, 1858; Larmande, 1985; Wall, 1991; Silverman ef al., 1995). In the first original report Foville com- pared the control of horizontal conjugate eye- movements to a man steering two horses by unit- ing the reins in each hand. The clinical findings in his patient could be explained by a unilateral pontine lesion although he lacked any patho- logical finding to support his hypothesis (Foville, 1858). Table 1. summarizes the lesion sites and the associated clinical syndromes in the four crossed paralyses. The brainstem, cerebellum and visual cortex receive their blood supplies from the posterior cir- culation (Wall, 1991; Simon and Ho, 1992; Kothari and Barson, 1996). Ischaemia in the vertebro- basilar circulation will lead to lesions with varied structural alterations and with a rostrocaudal or patchy localization (Hashizume et al., 1984; Wall, 1991). Hence a stroke in this area is characterized by very subile signs and symptoms like dizziness, vertigo, diplopia, ataxia, cranial nerve palsies and bilateral limb weakness (Hashizume et al., 1984; Wail, 1991; Henry, 1996; Kothari and Barson, 1996). The clinicopathological correlation will not always be precise for these symptoms and signs. However, involvement of the long tracts of the brainstem and deficits of cranial nerve nuclei are the hallmarks of a brainstem stroke (Wall, 1991; Simon and Ho, 1992; Silverman et al., 1995; Henry, 1996; Kothari and Barson, 1996). As already men- tioned, ipsilateral cranial nerve deficits with con- tralateral motor or sensory long-tract deficits are the most characteristic signs; hence the term ‘crossed paralyses’ (Wall, 1991; Simon and Ho, 1992; Silverman et al., 1995; Henry, 1996; Kothari and Barson, 1996). A RARE CASE OF DIPLOPIA Medial longitudinal fasciculus Lateral inferior pontine syndrome Medial inferior pontine syndrome Medial lemniscus 197 VI nucleus Paramedian pontine reticular formation VII nucleus Vi nucleus VII nerve VI nerve Spinothalamic tract Vi nerve Corticospinal and corticobulbar tracts Fig. 3. Cross-section through the inferior pons at the level of the VI nerve nucleus. Next we will focus on the symptoms and signs of the Foville’s syndrome. Common symptoms in patients with medial inferior pontine syndrome are contralateral weakness and numbness, ipsilat- eral total facial weakness and diplopia (Wall, 1991; Silverman et al., 1995). Physical examination will reveal a contralateral paralysis or paresis of the arm and the leg, an impaired tactile and pro- prioceptive sense over half of the body at the opposite site of the lesion and an internuclear ophthalmoplegia (Wall, 1991; Silverman et al., 1995). An internuclear ophthalmoplegia is charac- terized by an adduction paresis of one eye with a horizontal nystagmus in the contralateral eye when it is abducted (Larmande et al., 1973; Striano et al., 1990; Wall, 1991). The lesion which causes an internuclear ophthalmoplegia is localized in the medial longitudinal fasciculus between the nuclei of cranial nerve III and VI (Wall, 1991). In our patient we have an adduction paresis of the right eye with the presence of a horizontal nystagmus in the left eye on lateral gaze. Presence of an internuclear ophthalmoplegia is generally caused by a stroke in elderly patients and by mul- tiple sclerosis in young patients (Wall, 1991; Kothari and Barson, 1996). Ipsilateral signs of the medial inferior pontine syndrome are paresis of conjugate gaze to the site of the lesion and also to the oculocephalic manoeuvre if the nucleus of the cranial nerve VI is involved (Wall, 1991). Other ipsilateral signs are a one-and-a-half syndrome, a nystagmus, diplo- pia on lateral gaze and a peripheral type of facial palsy (Wall, 1991; Silverman et al., 1995). A one- and-a-half syndrome is the combination of an internuclear ophthalmoplegia on looking away from the lesion with a gaze palsy on looking toward the site of the lesion (Larmande et al., 1973; Striano et al., 1990; Wall, 1991). Our patient presented a typical one-and-a-half syndrome: on looking to the right (site of the lesion) he presented a gaze palsy; on looking to the left (away from the lesion) he presented an adduction paresis of the right eye with a horizontal nystag- mus of the left eye. The site of the lesion is the right paramedian pontine reticular formation or the nucleus of the cranial nerve VI. An extension of the lesion site with involvement of the inter- nuclear fibres crossing from the contralateral VI nerve nucleus is responsible for the internuclear ophthalmoplegia (Larmande et al., 1973; Striano et al., 1990; Wall, 1991). Figure 3 shows a cross-section through the in- ferior pons at the level of the nucleus of cranial nerve VI. The shaded areas are the lesion sites in case of a lateral and medial inferior pontine syn- drome. Occlusion of the median branches of the EUROPEAN JOURNAL OF EMERGENCY MEDICINE (1996) 3(3) 198 basilar artery is responsible for the Foville’s syn- drome. An occlusion of the anterior inferior cere- bellar artery leads to the lateral inferior pontine syndrome (Wall, 1991). As in our patient the diagnosis can be made on the clinical history and physical examination alone. Imaging techniques may be of assistance depending upon the circumstances (Wall, 1991; Simon and Ho, 1992; Kothari and Barson, 1996). CT scan without contrast is essential in differen- tiating ischaemic from haemorrhagic infarction (Wall, 1991; Simon and Ho, 1992; Kothari and Barson, 1996). The role of MRI in the emergency department is not well known, mostly due to its inavailability to every ED (Kothari and Barson, 1996). Ischaemic infarcts apparently can be visual- ized earlier by MRI than by conventional CT (Wall, 1991; Kothari and Barson, 1996). MRI is also more effective than CT in identifying acute posterior circulation strokes (Wall, 1991; Kothari and Barson, 1996). In our patient the MRI of the brain did not demonstrate ischaemic lesions in the pontine region. We also performed a brain perfusion-scintigraphy with Technetium-99m hexamethyl propylamine oxide (HMPAO) with acetazolamide _ stress- testing, which in our experience and in others can be used as a functional and non-invasive method to evaluate the vasodilatory reserve of the poster- ior circulation (Matsuda et al., 1991; Trouillas et al., 1991; Masdeu et al., 1994; Laureys et al., 1996). The standard to demonstrate stenoses, occlusions of large and small blood vessels in the brain defin- itely remains the angiography (Simon and Ho, 1992; Kothari and Barson, 1996). Angiography can detect subtle arterial abnormalities missed by other imaging techniques. Everybody should be aware of its cost, availability and invasiveness (Simon and Ho, 1992; Kothari and Barson, 1996). In conclusion we would like to emphasize the importance of a detailed clinical examination, including a detailed neurological examination in each patient presenting at the emergency depart- ment with a neurological disorder. As symptoms and signs can disappear within a few hours, the first assessment of the patient by the emergency physician is of great importance and is often the EUROPEAN JOURNAL OF EMERGENCY MEDICINE (1996) 3(3) HUBLOUE, LAUREYS and MICHOTTE key to the diagnosis. Furthermore diagnostic imaging techniques will not always be able to confirm the clinical diagnosis. ACKNOWLEDGEMENTS We thank Marc Terriere and Eddy Broodtaerts for their technical assistance in obtaining Figs 1, 2 and 3. REFERENCES Foville, A. (1858) Note sur une paralysie peu connue de certains muscles de l'oeil, et sa liaison avec quelques points de l’anatomie et la physiologie de la protubérance annulaire. Bull. Soc. Anat. Paris, 33, 393-414. Hashizume, Y., Kishimoto, H. and Iijima, S. 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