Ataxia, developmental delay and an extensive neuronal migration abnormality in 2 siblings

Two siblings with developmental delay and a non-progressive cerebellar ataxia are described. The electroencephalograms in both children showed a rather unusual pattern of high amplitude 10-12/s rhythms maximal anteriorly, while extensive neuronal migration abnormalities were apparent on Magnetic Resonance scans. There were no dysmorphic features, metabolic abnormalities, chromosomal defects or evidence of prenatal environmental toxins. It is considered that these siblings have an autosomal recessive neuronal migration defect which has not previously been reported.

Neurological deterioration in young adults with phenylketonuria

7 patients with phenylketonuria who developed neurological disability in adolescence or early adult life are described. 4 had been diagnosed by routine neonatal screening and started a low phenylalanine diet in infancy. 3 were diagnosed in early childhood because of developmental delay, and then started dietary treatment. Dietary control deteriorated in later years and was withdrawn in mid to late childhood. The late neurological deterioration cannot be directly ascribed to poor compliance with or cessation of dietary treatment in this small, retrospective study--but other likely causes have been excluded and 2 patients showed a striking clinical improvement when a strict diet was resumed. Serial magnetic resonance images from one of these patients show abnormalities that appeared after cessation of dietary treatment and resolved after diet was resumed. If these findings are confirmed, strict dietary control into adult life would be indicated for at least some patients with phenylketonuria.

Hemifacial spasm in infancy

Three infants presented with the onset of hemifacial spasm after birth and at the age of 10 months. One patient was found to have occlusion of the straight sinus and large collateral veins at the base of the brain, presumably due to venous sinus thrombosis, supporting the concept of vascular compression of the facial nerve at its exit from the brain stem as a mechanism for the production of hemifacial spasm. The other patients each had an intrinsic mass compressing the fourth ventricle, located in the lower pons and extending into the cerebellar vermis and right cerebellar peduncle in one; in the other patient, the mass involved the cerebellar vermis and right middle cerebellar peduncle alone. These patients widen the etiologic spectrum of the syndrome and show that serious intracranial diseases may underlie hemifacial spasm in infancy.

Computed tomography in the assessment of raised intracranial pressure in non-traumatic coma

Cranial computed tomography (CT) scans and invasive intracranial pressure (ICP) measurements were reviewed for 34 children with non-traumatic coma from various causes. CT scan features including focal or generalised changes in density were noted and changes in cerebrospinal fluid (CSF) spaces were graded and correlated with the level of maximum ICP in the first 12 hours of treatment and monitoring. Seven patients had normal findings and 27 had abnormal scans. Nineteen of the 27 patients with abnormal scans had generalised abnormalities with varying degrees of loss of CSF space. Seventeen of these 19 patients had pressures greater than 15 mmHg. The highest pressures being found in those with the greatest degree of CSF space obliteration. In the remaining 8 patients, who had focal abnormalities either within the basal ganglia or cerebral hemisphere, there was no relationship between local CSF space obliteration and the level of ICP. In the 7 patients with normal scans three had ICPs of 20 mmHg or greater in the first 12 hours of monitoring and a further two also developed an ICP of this level 13-36 hours after the initiation of monitoring. In non-traumatic coma of various causes there is an association between loss of CSF space and increased ICP. However, there were two important exceptions to this; firstly in patients with focal abnormalities either within the basal ganglia or cerebral hemisphere, in whom the loss of adjacent CSF spaces was not a good indicator of generalised raised ICP; secondly some patients with normal scans, in whom this finding did not indicate normal ICP nor ensure that it remained at this level.

An unusual complication of mourning

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Neurotoxicity in lymphoblastic leukaemia: comparison of oral and intramuscular methotrexate and two doses of radiation

Serial cranial computed tomograms were carried out in 136 children with acute lymphoblastic leukaemia who were receiving 24 Gy or 18 Gy of cranial irradiation and continuing treatment with doses of methotrexate given weekly orally or intramuscularly. The findings were correlated with treatment variables, the development of fits, and the intelligence quotient (IQ). Reversible brain shrinkage, attributed to treatment with steroids, was found on 87 of 114 initial scans (76%); 14 showed changes in white matter during treatment (10%), and calcification was found in 13 either during or after treatment (10%). Eight children (6%) had fits, and in six of the eight there were changes in white matter or calcification on the scans. Comparison of the two radiotherapy dosages showed no difference in the incidence of abnormalities seen on computed tomography, fits, or serial IQ measurements, but children receiving intramuscular methotrexate had a higher incidence of calcification and a lower mean IQ at one year than those who received the drug orally, although this difference was not apparent later. Younger children were more likely to develop changes on computed tomograms and fits, and to have low IQs on completion of treatment, with changes most apparent in those less than 2 years of age. There were highly significant correlations between abnormalities on computed tomography, fits, and IQ. These findings confirm the neurological vulnerability of younger children with acute lymphoblastic leukaemia, show an association between abnormalities on computed tomography and intellectual deficit, and suggest that methotrexate is more toxic when given intramuscularly than orally. They provide no evidence that 18 Gy of cranial irradiation is less toxic than 24 Gy, and indicate the need for alternative treatment regimens.

Convergence nystagmus associated with Arnold-Chiari malformation

A case of convergence nystagmus associated with an Arnold-Chiari type I malformation is presented. The nystagmus appeared in the absence of fixation, was provoked during Valsalva's maneuver and neck flexion and extension, and attenuated on deep inspiration. Sagittal magnetic resonance images showed that the diameter of the cerebral aqueduct increased with the neck in full flexion and in full extension. Surgical foramen magnum decompression considerably reduced the nystagmus and abolished the postural variation of aqueduct diameter. It is postulated that this nystagmus was due to a combination of mechanical distortion and abnormal transmission of cerebrospinal fluid pressure to the aqueductal region.

Joubert syndrome: a clinico-radiological study

A characteristic malformation of the cerebellum, including dysgenesis of the vermis and enlargement of the fourth ventricle was observed on computed tomography (CT) in 16 children on review of our consecutive material. Seven of these children underwent magnetic resonance imaging (MRI) which showed hypoplasia of the brainstem in addition to cerebellar vermian dysgenesis. One child had, in addition, dysgenesis of the corpus callosum. All these children were developmentally delayed, and many had neonatal breathing abnormalities, congenital retinal dystrophy and supranuclear ocular motor abnormalities. Joubert's syndrome should be suspected in children in whom dysgenesis of the cerebellar vermis and hypoplasia of the brainstem is shown on CT or MRI.

Epidural gas: an unusual complication of metastatic oesophageal carcinoma

Epidural gas occurring in benign disease is well documented. Gas formation within an epidural metastasis, which has not been previously reported, was demonstrated using computed myelography.

Central nervous system malformations in Mohr's syndrome

A boy with severe developmental delay, bilateral, symmetrical hallucal duplication, and accessory alveolar frenula was found to have radiological evidence of a large arachnoid cyst compressing the cerebellum and brain stem. We review neurological abnormalities in Mohr's syndrome.

Cranio-vertebral bony changes in a case of congenital lipomatosis

Congenital lipomatosis may cause a fatty mass infiltrating muscle planes and extending into the epidural space. Adjacent structures are displaced: there is pressure erosion of the vertebrae and periosteal new bone formation.

Intermittent disconjugate eye movements--a sign of raised intracranial pressure with brain stem compression

Two patients are reported who demonstrated disconjugate eye movements associated with raised intracranial pressure. This physical sign has not previously been recorded in association with raised intracranial pressure.

Balloon closure of a surgical aorto-atrial communication

Surgical repair of an extensive dissection of the proximal aorta (Shumway type A or DeBakey type I) was complicated by persistent haemorrhage from the surgical suture lines and via the false lumen. This was controlled by closing the aortic adventitia round the repaired aorta and by creating an anastomosis between the subadventitial space and the right atrial appendage. Though the haemorrhage was contained, the left to right (aorto-atrial) shunt led to a severe low output state, which was corrected by percutaneous closure of the fistula with a detachable balloon. A year after operation computed axial tomographic scanning showed the balloon in place though the para-aortic space persisted and communicated freely with the aorta.

MRI and hydrocephalus in childhood

In six young patients presenting with raised intracranial pressure during the period of a year, CT revealed the presence of hydrocephalus, but not the cause. Magnetic Resonance Imaging not only showed the site and nature of the obstructing lesion, but also detected additional clinically silent spinal cord tumors in five of the patients. The place of MRI in the diagnosis of diseases involving the region of the cranio-cervical junction and in the elucidation of "unexplained hydrocephalus" is considered.

Computed tomography in management of medulloblastomas

The neuroradiological studies of 116 patients with histologically verified medulloblastomas, which had been examined with plain and contrast-enhanced computed tomography (CT), were reviewed. The typical CT appearances of a well-defined, hyperdense enhancing mass in the vermis, with surrounding oedema, occurred in 60% of this series. Atypical features include calcification (17%), cystic or necrotic regions (47%) or poorly defined margins and lack of enhancement (7%). Such features in a vermis mass presenting in the first decade, especially in a boy, should not be considered against the diagnosis of medulloblastoma, but may be misleading when the tumour predominantly involves a cerebellar hemisphere.