Sequential MRI, SPECT and PET in respiratory syncytial virus encephalitis

We report on a 3-year-old girl with respiratory syncytial virus (RSV) encephalitis manifested by disturbance of consciousness, conjugate eye deviation, anuria, truncal ataxia and intention tremor. T2-weighted magnetic resonance imaging (MRI) showed hyperintense areas in the cerebellar cortex. No lesion was detected in the cerebral cortex, pons or spinal cord. The hyperintense areas in the cerebellar cortex diminished with recovery from the clinical manifestations and had resolved 2 months after onset. The MRI lesions in the cerebellum were considered to be due to oedema. SPECT and positron emission tomography (PET), performed 3 months after onset, disclosed areas of hypoperfusion and hypometabolism at the same sites. One year after onset, MRI showed mild atrophy of the cerebellum. Hypoperfusion on SPECT and hypometabolism on PET remained. Neuroimaging showed that ataxia and tremor in this case were the result of cerebellitis. The patient has no neurological deficit except for mild truncal ataxia. This patient is a rare example of RSV encephalitis. Received: 11 December 1997 Accepted: 3 July 1998     

Posterior fossa hemorrhage in newborns following vaccum extractor delivery]

AIM: To emphasize the risk of posterior fossa hemorrhage in newborns following vacuum extraction. PATIENTS AND METHODS: Over a period of 26 months (September 1996-December 1998), seven patients who underwent delivery with the vacuum extractor had symptoms of brain stem compression, related to posterior fossa hemorrhage. They were referred to the neonatal intensive care unit. Some parameters had been analyzed: gestational period, delivery circumstances, gestational age, parameters of newborn, indications of vacuum extraction and other paraclinical investigations (biological and radiological). RESULTS: Ultrasound scan revealed intracranial hemorrhage in five cases of seven; mean time of diagnosis was 10 hours of age. All patients presented symptoms of brain stem compression. Mean period of follow-up was 22 months: six of seven patients had a normal neurodevelopment. One patient had a cerebellar ataxia, another one a palsy of the IIIrd cranial nerve. CONCLUSION: Analyses of posterior fossa by ultrasound scan should be made for newborns delivered by vacuum extractor, especially if they had symptoms of brain stem compression.     

Characteristic MR features of encephalitis caused by Epstein-Barr virus: a case report

An 8-year-old girl showed symptoms of encephalitis during acute Epstein-Barr virus (EBV) infection. The diagnosis of EB virus infection was made by changes in the titres of EB virus-specific antibody. Cranial MRI demonstrated abnormal low and high signal intensities in the striatal body (putamen and caudate nucleus) on T1-weighted and T2-weighted images, respectively, during the acute phase. These abnormal findings had almost completely resolved 1 month later. EBV infection should be considered when lesions are localised to the basal ganglia. Received: 5 May 1997 Accepted: 6 February 1998     

Successful use of intracavitary bleomycin for low-grade astrocytoma tumor cyst

We report successful use of bleomycin in a low-grade astrocytoma tumor cyst of the tectal plate. A 6-year-old male underwent subtotal resection of a low-grade astrocytoma of the tectal plate followed by chemotherapy and proton beam radiation at age 2 and a half. Despite resolution of the solid portion of the tumor, serial MRI showed enlargement of a bilobar tumor cyst 3 years after the original diagnosis. The patient developed progressive ataxia, short-term memory loss and dysconjugate gaze. Following stereotactic placement of an Ommaya reservoir into the cyst, Isovue contrast and CT scan were used to confirm the integrity of the cyst. Five consecutive daily doses of 3.0 mg of bleomycin were instilled into the cyst after removal of cyst fluid. The therapy was well tolerated in the outpatient setting, and the clinical findings resolved. Subsequent CT and MRI at 4 months and 2 years after bleomycin confirmed no recurrence of the tumor or cyst.     

Rhombencephalosynapsis: Association with single umbilical artery

A 6-year-old girl who presented with developmental delay and non-progressive ataxia is described. MRI of brain showed agenesis of cerebellar vermis with fusion of cerebellar hemispheres and dentate nuclei. MRI findings were characteristic of Rhombencephalosynapsis. Partial agenesis of corpus callosum and absent septum pellucidum were also seen. The child had also been noted to have a single umbilical artery at birth: a hitherto undescribed association.     

Central nervous system imaging and congenital melanocytic naevi.

AIM: To establish the prevalence of central nervous system (CNS) abnormalities on magnetic resonance imaging (MRI) in a population of children with congenital melanocytic naevi (CMN) over the head and/or spine, and to compare this with clinical findings. METHODS: Forty three patients identified from outpatient clinics underwent MRI of the brain and/or spine. These were reported by a paediatric radiologist and findings compared with the clinical picture. RESULTS: Nine patients had abnormal clinical neurology, seven had abnormal findings on MRI, and six had both abnormal clinical and radiological findings. Only three of the abnormal MRIs showed features of intracranial melanosis. Three others showed structural brain abnormalities: one choroid plexus papilloma, one cerebellar astrocytoma, and one posterior fossa arachnoid cyst; the first two of these have not previously been described in association with CMN. The last abnormal MRI showed equivocal changes requiring reimaging. CONCLUSIONS: The prevalence of radiological CNS abnormality in this group of children was 7/43. Six of these developed abnormal clinical neurological signs within the first 18 months of life, but two did not do so until after the MRI. Two of the CNS lesions were operable; for this reason we support the routine use of early MRI in this group.     

Magnetic resonance imaging of the brain in congenital cytomegalovirus infection

Ten children (age 2 months to 8 years) with a congenital cytomegalovirus (CMV) infection were studied by magnetic resonance imaging (MRI) using a 2.35 Tesla magnet. CMV infection was confirmed by serological investigations and virus culture in the neonatal period. Nine children had severe mental retardation and cerebral palsy, 1 patient suffered from microcephaly, ataxia and deafness. The cranial MRI examination showed the following abnormalities (N): dilated lateral ventricles (10) and subarachnoid space (8), oligo/pachygyria (8), delayed/pathological myelination (7), paraventricular cysts (6), intracerebral calcification (1). This lack of sensitivity for calcification is explainable by the basic principles of MRI. The paraventricular cystic lesions were adjacent to the occipital horns of the lateral ventricles and separated only by a thin membrane. This finding might represent a “new sign” for congenital CMV infection in MRI examinations, being characteristic but nevertheless nonspecific, like calcification in CT. Presented in part at the ESPR meeting in Montreux 1988.     

Outcome of neonatal stroke in full-term infants without significant birth asphyxia

Seven children with neonatal stroke were identified and six were followed for 13 months to 5 years (mean 28 months). Gestational age ranged between 39 and 42 weeks and none had hypoxic ischaemic encephalopathy. Focal clonic seizures were the presenting feature in six, and one presented with apnoea. The age of the first seizure ranged between 8 and 48 h (mean 26). The total number of seizures ranged between 3 and 10 (mean 5), and all seizures resolved by day 3 in all cases. CT scan showed an ischaemic infarct in six cases, and one child had a haemorrhagic infarct in the right anterior cerebral artery distribution. Phenobarbital was maintained for 3 weeks to 6 months (mean 11 weeks). None had recurrent seizures beyond the 3rd day of life and all were developing normally with no significant focal neurological deficits on follow up assessment. Conclusions Full-term infants with neonatal stroke unrelated to significant birth asphyxia have a favourable neurological outcome. Seizures appear to be restricted to the first 3 days of life. We recommend short-term treatment with anticonvulsants. Received: 15 May 1997 / Accepted in revised form: 5 December 1997     

Biotinidase deficiency: the importance of adequate follow-up for an inconclusive newborn screening result

Biotinidase deficiency is an inherited metabolic disorder characterized by inability to recycle protein-bound biotin. It usually presents with ataxia and seizures, though atypical presentations have also been described. We report a 15-month-old boy with profound biotinidase deficiency who presented with laryngeal stridor and subsequently developed severe ataxia and lactic acidosis. Subsequently, it was discovered that the patients newborn screening test for biotinidase activity had been inconclusive, but confirmatory testing had not been done. Brain magnetic resonance imaging showed multiple white matter non-enhancing T2 hyperintensities, which largely resolved following 6 months of biotin therapy; however, there was residual deafness and mental retardation. Conclusion:An argument is made for universal newborn screening in biotinidase deficiency and improved mechanisms for follow-up of positive screens, because delay in diagnosis results in irreversible morbidity, newborn screening is cost effective, and early therapy prevents the neurologic sequelae.     

Congenital bronchoesophageal fistula in childhood

A case of congenital bronchoesophageal fistula in a 9-month-old infant is presented. He had had repeated pulmonary infections since he was 2 months old. A barium swallow examination showed a communicating fistula between the mid-esophagus and the posterior segmental bronchus of the right upper lobe. MRI clearly demonstrated the course of the fistula.     

An early-onset case of multiple sclerosis with thalamic lesions on MRI

We present here an early-onset case of multiple sclerosis (MS) with thalamic lesions. The patient first experienced an episode of ataxic gait at 2 years 3 months of age, with spontaneous remission within 1 month. At 5 years 4 months, she was admitted because of cerebellar ataxia, oculomotor restriction and feeding difficulty. Magnetic resonance imaging (MRI) showed multiple well-defined lesions in the white matter of the cerebellum, mid-brain, periventricle and right frontal lobe. Cerebrospinal fluid (CSF) showed a mild elevation of both immunoglobulin G (IgG) and myelin basic protein (MBP). Serum anti-myelin antibody was also positive, although leukocytosis and elevation of C-reactive protein were not found. Methylprednisolone pulse therapy relieved symptoms within 2 weeks and the abnormal MRI and CSF findings gradually improved. At 6 years 6 months of age, she incurred a third episode of cerebellar ataxia and disturbance of consciousness. Magnetic resonance imaging revealed recurrence and extension of the previous lesions as well as new lesions in the thalamus and internal capsule. CSF IgG and MBP level showed a higher elevation than in the second episode. The combination of the cerebellar, brain-stem, cerebral and thalamic lesions with remission and exacerbation, supported by MRI and CSF findings, allowed the diagnosis of clinically definite MS to be made. This is one of the youngest cases of MS yet described, with the first attack occurring at 27 months of age. In addition, this case is unique for the involvement of the gray matter in the thalamus.     

Popliteal entrapment syndrome: non-invasive diagnosis and complete recovery after surgery in an 11-year-old boy

We present an unusual case of popliteal entrapment syndrome type I in an 11-year-old boy. Presenting symptoms were exercise-related pain and pallor in his left lower leg. The diagnosis of popliteal entrapment syndrome was established by acral plethysmography, colour-coded Doppler sonography and MRI. After myotomy of the gastrocnemius muscle the symptoms resolved completely. Post-operative duplex scan showed normal blood flow, even in plantar flexion of the foot. Received: 10 October 1997 Accepted: 17 June 1998     

Paraneoplastic cerebellar degeneration and Horner syndrome: association of two uncommon findings in a child with Hodgkin disease

An 11-year-old boy admitted with a right cervical mass was found to have Hodgkin disease. On admission, he also had right Homer syndrome and severe cerebellar ataxia. Cranial MRI revealed marked cerebellar atrophy. He was treated with chemotherapy consisting of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD), in addition to radiotherapy. Three months after initiation of therapy, he had a partial remission of tumor. Neurologic symptoms improved dramatically after chemotherapy started. Hodgkin disease should be included in the differential diagnosis of children with cerebellar findings and Horner syndrome.     

Mutism after posterior fossa tumour resection in children: incomplete recovery on long-term follow-up

INTRODUCTION: Mutism after posterior fossa tumour resection is generally said to be transient. Our experience suggested that speech did not usually normalise, and that mutism was associated with neurologic deficits that did not recover fully. METHODS: Children with mutism after posterior fossa tumour resection, and alive more than 2 years post-operatively, were reviewed retrospectively. Charts were reviewed and parents contacted to ascertain details about mutism, associated neurologic deficits, and the most recent speech and neurologic status. RESULTS: There were 7 children, with follow-up ranging from 2.5 to 13.1 years (mean 6.8 years). Tumours were midline, with 4 astrocytomas and 3 medulloblastomas. Mutism was noted immediately after post-operative extubation in all patients. Speech reappeared 1-15 weeks post-operatively, except for 1 patient, who remained mute at 2.5 years. Speech returned to normal in only 1 patient. Mutism was always accompanied by new or worsened cerebellar ataxia, which resolved incompletely in the long term. Sixth nerve palsies occurred in 3 and recovered incompletely. Seventh nerve paresis occurred in 2 and recovered completely. CONCLUSION: Mutism after posterior fossa tumour resection is associated with other neurologic deficits, particularly ataxia. Whereas speech usually returns, contrary to general opinion, speech rarely normalises. Other associated deficits rarely resolve completely. These findings have significant implications for counselling of family and patients.     

Ultrasound and MR imaging of fibromatosis colli (sternomastoid tumor of infancy)

The sonographic and CT findings of fibromatosis colli (sternomastoid tumor of infancy) have been described, but the MRI appearance has been reported in only one case in which the mass resolved over time. This case describes the detailed MRI findings in a biopsy-proven case of fibromatosis colli; the signal intensity of the mass on T2-weighted images was slightly less than on gradient-recalled T1-weighted images, consistent with the presence of some fibrous tissue within the muscle mass. The involved portion of the muscle was better defined on MRI than sonography. MRI was helpful in demonstrating the signal characteristics of the mass; localizing the mass to within the sternocleidomastoid muscle; and demonstrating clear surrounding fascial planes with lack of associated lymphadenopathy, airway compression, vascular encasement, bone involvement or intracranial/intraspinal extension associated with other neck masses. Received: 12 August 1997 Accepted: 21 November 1997     

Krabbe disease--clinical profile

OBJECTIVE: To study clinical features and investigations of children with Krabbe Disease (KD). DESIGN: Retrospective. SETTING: Genetic Clinic of a tertiary care teaching hospital. METHODS: Hospital records of patients with enzymatically confirmed KD were analyzed with respect to their clinical features and investigations including neuroimaging (CT-scan and/or MRI). Galactocerebrosidase (GALC) activity was estimated photometrically in the peripheral blood leukocytes. RESULTS: Nine children (age ranging from 2 1/2 months to 8 years) were studied, of which 5 had the classical infantile disease, 3 had late infantile form and one was diagnosed as juvenile KD. GALC levels in peripheral blood leukocytes were low or absent in all. Most of the children with infantile disease presented with neurodegeneration, seizures or fever. Optic atrophy was uncommon in our series (present only in a single case). Majority of the cases had elevated cerebrospinal fluid (CSF) protein levels and peripheral neuropathy on nerve conduction (NC) studies. Findings typical of KD were noted in 7 patients who underwent magnetic resonance imaging (MRI). The sole patient with juvenile disease presented with developmental delay and progressive spastic quadriparesis. CONCLUSION: Krabbe disease should be considered in the differential diagnosis of early infantile onset of neurodegeneration with seizures. Likewise, older children with progressive ataxia or spastic quadriparesis in whom the etiology remains obscure, must be investigated for Krabbe disease. MRI can be diagnostic in absence of availability of enzyme diagnosis.     

Reformation of the posterior atlanto-occipital membrane following posterior fossa decompression with subsequent constriction at the craniocervical junction

The posterior atlanto-occipital membrane (PAO) contributes little to craniocervical stability and is generally underappreciated and incised with most suboccipital craniectomies. We report a case of a child who underwent posterior fossa decompression for Chiari I malformation with syringomyelia whose symptoms had not resolved months after surgery. A secondary exploratory operation revealed a healed constricting PAO which had been incised linearly at the initial operation. This patient's symptoms improved soon after the second surgery. We propose that attention be given to this membrane, and if it is incised with underlying dura mater as in a standard posterior fossa decompression, it should be removed or cauterized separately and laterally to inhibit its reformation.     

Complex partial seizure mimicking psychotic reaction in an adolescent

A previously healthy 15-year-old boy initially diagnosed to have acute psychotic reaction had a history of a single generalized seizure and prolonged amnestic states of varying intensity and duration. An ictal electroencephalogram (EEG) showed bitemporal ictal discharges starting from the left side. Carbamazepine was started. A magnetic resonance imaging (MRI) obtained on the 10th day of the antiepileptic therapy showed increased signal intensity on the T2 weighted images. The patient's memory function markedly improved during 10 months' follow-up with antiepileptic treatment, although he described brief attacks of dizziness. A repeat MRI examination showed normal findings. The amnesticstates were thought to be due to frequent complex partial seizures, and transient MRI changes to hippocampal edema. This case illustrates the importance of epileptic disorders in the differential diagnosis of psychiatric conditions.     

The natural history of ventriculomegaly and tonsillar herniation in children with posterior fossa tumours--an MRI study

OBJECTIVE: Posterior fossa tumours in children predispose to hydrocephalus, although the natural history is unclear and the need for drainage of the ventricles is controversial. We report on the natural history of ventriculomegaly and tonsillar herniation, as seen on serial MRI scans in children with posterior fossa tumours. RESULTS: Eighty-nine children with posterior fossa tumours were reviewed retrospectively. Overall, 18 (20%) patients required permanent cerebrospinal fluid (CSF) drainage in the form of a ventriculoperitoneal shunt (n = 15) or third ventriculostomy (n = 3). On pre-operative MRI scan, the ventricular size was assessed by measurement of the ventricular index (VI) and 59 patients (66%) had a VI greater than 0.4. There was a progressive decrease in the mean VI from pre-operative to post-operative MRI scans and beyond 3-9 months after surgery, the mean VI was less than 0.4 (p = 0.0001). Patients requiring permanent CSF drainage had a greater VI pre-operatively and at 3-9 months post-operatively (p < 0.05). On pre-operative MRI scan, 75 patients (84%) had greater than 5 mm herniation of the cerebellar tonsils below the level of the foramen magnum. There was a progressive decrease in the mean tonsillar herniation from pre-operative to post-operative MRI scans, with time (p = 0.0001), although this did not relate to the need for CSF drainage. On multivariate analysis, the need for permanent CSF drainage was associated with pre- and intra-operative CSF drainage (odds ratio = 23.3; p = 0.0001) and incomplete surgical excision of tumour (odds ratio = 7.7; p = 0.006). CONCLUSIONS: Hydrocephalus and tonsillar herniation are common in children with posterior fossa tumours, although post-operatively there is a natural tendency for it to resolve and only a fifth of the patients needed permanent CSF drainage. We recommend selective drainage of CSF in children with posterior fossa tumours. Patients at risk are those with severe symptoms at presentation, needing peri-operative CSF drainage and those with subtotal resection of tumour.     

Hypothalamic-pituitary vascularization in pituitary stalk transection syndrome: is the pituitary stalk really transected?

We examined 14 patients, aged 10–25 years, with idiopathic hypopituitarism. All presented an ectopic posterior pituitary at the median eminence with a hypoplastic anterior pituitary on magnetic resonance imaging (MRI). Eight patients had isolated growth hormone deficit (IGHD) and six had multiple hormone deficits (MPHD). Unenhanced MRI showed the pituitary stalk, which was extremely thin, in only three patients, while T1-weighted images obtained after intravenous injection of gadopentetate dimeglumine (Gd-DTPA) showed a thin pituitary stalk in seven patients (six with IGHD and one with MPHD), demonstrating a preserved vascular component of the stalk. MRI with Gd-DTPA was more sensitive than unenhanced MRI in detecting the pituitary stalk in patients with hypopituitarism with an ectopic posterior pituitary: the stalk was demonstrated in 50 % of the cases (seven patients), versus 21.4 % (three patients) by unenhanced MRI. The dynamic study of the hypothalamo-hypophyseal axis performed with turbo-FLASH sequences after bolus injection of Gd-DTPA showed the residual anterior pituitary to have arterial enhancement times, which suggests that an arterial system compensates for the absent or diminished blood supply from the portal system, independent of stalk detection. Received: 23 January 1996 Accepted: 31 January 1996