Posterior Fossa Subdural Hematomas in Neonates Nathan K. Blank, MD; Roy Strand, MD; Floyd H. Gilles, MD; Agasanakatte Palakshappa, MD \s=b\ Posterior fossa subdural hematomas in the newborn infant are rare but potentially treatable. The infants are normal after birth, but within days, hydrocephalus hypotonia, and irregular respirations develop. Seizures and third nerve pareses are unusual. We report a neonate in whom this process was identified by computerized tomographic brain scan. We also discuss potential misinterpretations of the computerized tomographic brain scan in neonates. (Arch Neurol 35:108-111, 1978) fossa subdural hema¬ tomas in newborn infants are less Posterior frequent than those located supratentorially in autopsy series.1 Eight cases of clinically identified infratentorial subdural hematomas have been de¬ scribed in the literature. Unfortu¬ nately, neurologic consultants do not always consider this rare but poten¬ tially treatable entity.--7 We report a newborn infant with a computerized tomographic (CT) brain scan of a posterior fossa subdural hematoma. Accepted for publication July 7, 1977. From the Departments of Pathology (Dr Palakshappa), Neuropathology (Drs Blank and Gilles), and Radiology (Dr Strand), Children's Hospital Medical Center and the Boston Hospital for Women, and the Departments of Neurology\x=req-\ Neuropathology (Drs Blank and Gilles) and Radiology (Dr Strand), Harvard Medical School, Boston. Reprint requests to the Department of Pathology (Neuropathology) the Children's Hospital Medical Center, 300 Longwood Ave, Boston, MA 02115 (Dr Gilles). This case also emphasizes a potential pitfall in interpretation of germinal matrix hemorrhages in neonates with CT scans and stresses the need for continuous pathologic correlations. REPORT OF A CASE This 3.2 kg male full-term infant was born of an uncomplicated (gravida 3, para 0, abortus 2) pregnancy. The uneventful ten-hour labor was followed by a vaginal vertex delivery without the aid of forceps. The Apgar scores were 9 at one and five minutes, and head molding and facial ecchymosis were absent. On the fourth day, the child was noted to be jaundiced, lethar¬ gic, and irritable, with a weak cry, irreg¬ ular shallow respirations, and a pulse of 100 beats per minute. Subsequently, respira¬ tory arrest occurred. Rapid resuscitation was successful, though he required intuba¬ tion and assisted ventilation. After arrest, the pupils were fixed and dilated and opisthotonic posturing occurred. The hematocrit value was 31%, WBC count was 24,400 cu mm, blood cultures were negative, coag¬ ulation studies were normal, and the serum electrolyte level and blood chemistry studies were normal, except for an elevated direct bilirubin level. The lumbar puncture showed bloody CSF. The next day, opisthotonic posturing, irregular respirations, and tense fontanelle continued. The discs were flat, the retinae were free of hemorrhage, and the pupils were equal and reactive. The eyes were deviated to the left, with the left eye skewed slightly upward and did not pass the midline on doll's head maneuver. There was marked generalized hypotonia, but the child moved all extremities. The Moro and suck reflexes were absent, the tendon reflexes were hypoactive, and the plantar responses were extensor. On the sixth day, the CT scan showed a large collection of blood within the posterior fossa as well as dilation of the frontal, temporal, and occipital portions of the lateral ventricles. Blood was also described in the region of both caudate nuclei (Fig 1 and 2). The infant died the following day. The general autopsy was unremarkable except for diffuse and acute pulmonary hemorrhage. At the time of brain removal, a large collection of blood was found within the subdural space infratentorially. A small amount of subarachnoid hemorrhage accumulated adjacent to the exits of the lateral recesses and over the convexities. There were small pools of blood within the falx and tentorium. An incomplete tear of the inferior leaflet of the left tentorium extended 1 cm posteriorly from the free edge. Tears were not present within the lateral or straight sinuses, falx, or great vein of Galen. The superior aspect of the cerebellum was compressed and indented, and the lateral hemispheres displaced ante¬ riorly toward the clivus (Fig 3). The ventral pons and upper medulla were compressed anteriorly and medially against the clivus, and the upper fourth ventricle was obstructed by displaced vermal portions of the cerebellum. The cerebrum, which was coronally sectioned after fixation, con¬ tained a small collection of blood within the right occipital horn. The few remnants of choroid plexus available for study did not disclose the site of hemorrhage. The caudate nuclei and the adjacent subepen- dymal region were not hemorrhagic, con¬ trary to the interpretation of the CT scan. The frontal, occipital, and temporal por¬ tions of the lateral ventricles were moder¬ ately enlarged and the superior angles were blunted (Fig 4). Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/31/2015 are adjacent Fig 1—Computerized tomographic scan in axial projection. A and representations of 13-mm thickness, with 1 mm of overlapping. A is anatomically inferior to and right-sided structures are on right. On A, anterior clinoids (c) and petrous bones (p) are identified. Dorsum sellae are just posterior to anterior clinoids. On B, there is asymmetrical forward displacement of cerebellum (arrow heads) by intracranial substance, with density readings consistent with clotted blood. Fourth ventricle is not detectable. Dilated temporal horns and anterior horns of lateral ventricles are present (arrows). On microscopic examination, the com¬ pressed portions of the cerebellum con¬ tained eosinophilic Purkinje cells and karyorrhectic internal granule cells. The cerebellar deep white matter was gliotic and contained acutely swollen axons. The basis pontis adjacent to the clivus was also locally injured. In this region, neurons were necrotic, and the descending and crossing fiber bundles contained hypertrophic astrocytes and markedly swollen axons. Hypertrophie astrocytes, without necrosis or hemorrhage, were present in the deep cerebral white matter. The cortex, subcortical gray matter, and cord were otherwise normal. The caudate nuclei and the subependymal region were not hemorrhagic, and the germinal matrix was normally depleted. COMMENT Posterior fossa subdural hematoma in the newborn infant is a relatively rare event but must be considered in all infants who display progressive signs of neurologic dysfunction. The child in this report, unfortunately, died prior to surgical intervention, though the CT scan of the head was consistent with this diagnosis. The site of bleeding was a rent in the inferior leaflet of the tentorium cere¬ belli. The blood accumulated within the subdural space of the posterior fossa, compressed the cerebellum, ob¬ structed the fourth ventricle, and displaced the brain stem anteriorly and ventrally against the clivus. Microscopic evidence of severe and acute injury to these regions agrees with the clinical events noted in the infant. The drop in the hematocrit value, from 47% to 31%, and the eleva¬ tion of serum bilirubin level presum¬ ably reflect the intracranial hemor¬ rhage. The diffuse pulmonary hemor¬ rhage commonly found in neonatal autopsy series as a terminal event, has been associated with intracranial hy¬ pertension." Craig1 reported that six of ten neonates with subdural hemor¬ rhages who died within 36 hours of birth also had pulmonary hemor¬ rhages. Only eight newborn term infants have been described with clinically identified infratentorial subdural hemorrhages and five survived after surgical treatment. The clinical find¬ ings in these eight cases are compared with the present case in the Table. All of the neonates were full-term in¬ fants, the smallest weighing 3,200 gm. Information with respect to difficult labor or delivery was not always avail¬ able. A lag period from half a day to four days between birth and the onset of neurologic signs was characteristic and is of clinical significance in differ¬ entiating small continuing hemorrhagic leaks that accumulate infratentorially from sudden massive hem¬ orrhages secondary to durai sinus lacerations, avulsions of the vein of Galen, or hematomas, with rupture into the subdural space. The massive hemorrhages are associated with rap¬ id and progressive neurologic dys¬ function that usually occur immedi¬ ately after birth. Several of the cases with intracerebellar hematomas and rupture into the subdural space have been salvaged with rapid surgical decompression." '" The development of hydrocephalus, which is heralded by tense anterior fontanelle and increas¬ ing head circumference, is universally found in these infants and is usually the sign that instigates further neuro¬ logical evaluation. The hydrocephalus, at least initially, is related to the cerebellar compression of the fourth ventricle and/or the outlets of the fourth ventricle. Several of the pa¬ tients who were successfully treated subsequently displayed communicat¬ ing hydrocephalus and required ven¬ tricular shunts.1" The diagnosis of intraventricular hemorrhage is made in many of these infants, based on bloody ventricular and lumbar CSF, but the source of this minor ventric¬ ular hemorrhage is often not appar¬ ent. These children display early, nonspecific signs of impending neuro¬ logic collapse such as weak cry, lethargy, irritability, vomiting, and loss of Moro and suck reflexes, which are usually followed by signs referable to the posterior fossa, abnormal respi¬ rations, and hypotonia. Skew devia¬ tion, nystagmus, and sixth nerve pareses are the only major cranial nerve deficits and signs of focality that occasionally occur in this group. It is important to note the absence of third nerve paresis in these infants, a finding that is common in supratentorial masses such as subdural hemato- Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/31/2015 arises from small tears in the tentorial leaflets or from torn bridging veins that arise from the superior surfaces of the cerebellum.11'- These lacerations and avulsions presumably result from stress on the head during delivery. The CT scan is useful in identifying posterior fossa subdural hematomas. Birth weight, gm Delivery Onset of symptom Tense fontanelle Increase in head circumference Ventricular dilation Abnormal respiration Lethargy, irritability Loss of Moro's reflex Loss of suck reflex Abnormal tone Vomiting Fig 2.—Computerized tomographic scan axial projection, through brain directly above position of Fig 1, with A anatomically below B. A is at level of tentorial attachment posteriorly, and clotted blood density is seen in close relationship to tentorium between posterior aspect of two hemispheres (paired arrows). Lateral ventricles are mildly dilated. On B, clotted blood density is seen in right occipital horn (o). Same densities were found in interhemispheric fissure (i) and over quadrigeminal plate cistern (q). Blood clot was interpreted to be present just lateral to anterior horns in caudate nuclei (single arrows) as well. Last observation was erroneous (see text). Abnormal cry Seizures CSF Abnormal pupil reaction Other deficits Surgical therapy Results Communicating hydrocephalus Fig 3.—Bilaterally, there are concave depressions of superior aspect of cerebellum by hematomas. Ventral aspect of pons is flattened, and rostral fourth ventricle is collapsed. mas. Seizures are not commonly pres¬ ent. Most of the evidence points to head molding at the time of birth as the essential factor in the production of posterior fossa subdural hemato¬ mas.1"12 The massive hemorrhages that cause severe neurologic complica- Fig 4.—Lateral ventricles are enlarged, with rounded lateral angles. Diffuse subarachnoid hemorrhage is present. There is no subependymal hemorrhage over caudate. tions at birth or shortly thereafter are usually related to tears of the falx or tentorium cerebelli, with extension into the adjacent lateral or straight sinuses. Avulsion of the vein of Galen will also produce rapid death. In contrast, the slow accumulation of blood in the infratentorial region arises from small tears in the tentorial leaflets or from torn bridging veins that arise from the superior surfaces of the cerebellum.11'- These lacerations and avulsions presumably result from stress on the head during delivery. The CT scan is useful in identifying posterior fossa subdural hematomas. Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/31/2015 finical Findings in Patients Cases Coblentz2 3,711 Occipital caput; Relgh & Nelson3 3,859 Breech; easy low forceps delivery 4 days 10hr Pytlyk et al4 3,940 Vertex; forceps Nelson5 3,732 Vertex; forceps; easy delivery 16 hr 24 hr Carter & Pitt ma 6 3,236 Vertex; outlet Gilles & Shillito· Caso 1 3,219 Vertex; low Case 2 3,517 Breech difficult forceps forceps delivery 12hr 48 hr 4 days Case 3 4,317 Vertex; induced NR NR NR NR NR NR easy 52 hr 4 days + NR NR NR Vertex; delivery +* NR Present Case 3,200 NR NR NR NR NR NR NR NR + Xanthrochromic Bloody NR Bloody Bloody Bloody NR 0 NR Nystagmus Sixth nerve 0 Bloody Bloody NR NR Bilateral sixth palsy Bloody Skew eye deviation nerve paresis + Excellent Excellent Satisfactory Good Retarded Post¬ operative death + Post¬ operative death indicates present; 0, absent; and NR, not recorded. It must be emphasized, however, that this process should be suspected prior to the CT scan in order that the proper cuts can be obtained. From our case, a second important point can be emphasized. The in¬ creased densities in the region of the caudate nuclei could be interpreted as intraparenchymal or subependymal hemorrhages, when, in fact, they were actually pooled intraventricular blood overlying the head of the caudate nuclei. This fortuitous superimposi¬ tion of intraventricular blood is of clinical importance since in premature infants this area is the site of the germinal matrix or ganglionic emi¬ nence, which, in turn, is a major source of intraventricular hemorrhage. Again, this type of problem re-empha¬ sizes the continued necessity of patho¬ logic correlation with CT scan in order to become aware of artifacts that could be erroneously interpreted as specific processes. After a period of normalcy, any term newborn infant in whom a tense fontanelle, increasing head circumfer- enee, lethargy, irritability, and respi¬ ratory irregularities develops should be evaluated for a posterior fossa subdural hematoma. If a CT scan is readily available, the clinician in¬ volved in interpretation should be made aware of the possibility of posterior fossa hemorrhage so that the correct levels of scans are made and that the durai sinuses are distin¬ guished from hemorrhage. If the CT scan is not available, supratentorial and, if necessary, infratentorial sub¬ dural taps should be done.13 The elapsed time must be minimized in order to salvage the infant and perhaps prevent secondary communi¬ cating hydrocephalus. This study was supported in part by United Cerebral Palsy Research and Educational Foun¬ dation grant R-224-74, The Children's Hospital Medical Center Mental Retardation, and Human Development Research Program grant 5 P30 HDO 6276, and National Institute of Neurolog¬ ical and Communicative Diseases and Stroke grant 5 POI NS09704. References 1. Craig WS: Intracranial hemorrhage in the newborn. Arch Dis Child 13:89-124, 1938. 2. Coblentz RG: Cerebellar subdural hematoma in infant two weeks old with secondary hydrocephalus. Surgery 8:771-776, 1940. 3. Reigh EE, Nelson M: Posterior-fossa subdural hematoma with secondary hydrocephalus. J Neurosurg 19:346-348, 1962. 4. Pytlyk PJ, Miller RH, Stayura LA: Subdural hematoma of the posterior fossa: Report of a case. Pediatrics 40:436-439, 1967. 5. Nelson TY: Acute subdural haematoma in the posterior fossa. Med J Aust 2:792-795, 1959. 6. Carter LP, Pittman HW: Posterior fossa subdural hematoma of the newborn. J Neurosurg 34:423-426, 1971. 7. Gilles FH, Shillito J: Infantile hydrocephalus: Retrocerebellar subdural hematoma. J Pediatr 76:529-537, 1970. 8. McAdams AJ: Pulmonary hemorrhage on the newborn. Am J Dis Child 113:255-262, 1967. 9. Schreiber MS: Posterior fossa (cerebellar) haematoma in the newborn. Med J Aust 2:713\x=req-\ 715, 1963. 10. Rothballer AB: Traumatic cerebellar hematoma in the newborn: Case report of operative removal with survival. J Neurosurg 19:913-915, 1962. 11. Holland E: Cranial stress in the foetus during labour and on the effects of excessive stress on the intracranial contents: With an analysis of eighty-one cases of torn tentorium cerebelli and subdural cerebral haemorrhage. J Obstet Gynecol Br Empire 29:549-571, 1922. 12. Potter EL, Craig JM: Pathology of the Fetus and the Infant. Chicago, Year Book Medical Publishers Inc, 1975. 13. Matson D, in the discussion of Collins WF: Subdural hematomas of infancy. Clin Neurosurg 15:403, 1967. Downloaded From: http://archneur.jamanetwork.com/ by a Karolinska Institutet University Library User on 05/31/2015