Subacute sclerosing panencephalitis: brain stem involvement in a peculiar pattern

The most common pattern in subacute sclerosing panencephalitis, is in the cerebral hemisphere white matter on T2-weighted images with or without atrophy. Brain-stem lesions are rare. We report brain-stem involvement in two children with subacute sclerosing panencephalitis. A peculiar pattern, with involvement of the pons with extension to both middle cerebellar peduncles and substantia nigra but sparing the pontine tegmentum, is suggested. Received: 10 January 2000/Accepted: 18 April 2000     

Primary central nervous system immunocytoma: MRI and spectroscopy

We report on a young woman with a primary cerebral immunocytoma. Most primary cerebral nervous system lymphomas (PCNSL) are highly malignant undifferentiated B-cell tumours, there are few data on the clinical course, MRI and spectroscopy findings of this rare PCNSL subtype. MRI revealed a radially enhancing tumour with mild perifocal oedema. MR spectroscopy indicated low cell turnover. Slow clinical progression, no significant changes with treatment, and imaging findings were consistent with a low-grade malignant tumour. Received: 21 January 2000/Accepted: 15 February 2000     

A residual cystic lesion in acute disseminated encephalomyelitis

We report a case of acute disseminated encephalomyelitis (ADEM) with a residual cystic lesion on MRI. This seemed to be induced by Japanese encephalitis vaccination. Despite complete clinical improvement with high-dose steroid therapy, the cystic lesion has persisted for 3 years on MRI. There have been no previous reports of residual cystic lesions in ADEM. Received: 20 August 1999/Accepted: 11 November 1999     

Neuroradiological and clinical findings in rhombencephalosynapsis

Rhombencephalosynapsis is an unusual disorder characterised by maldevelopment of the rhombencephalon, sometimes with supratentorial midline anomalies. We report MRI findings in a 39-year-old woman, the oldest in the literature. MRI demonstrated hypoplasia of the cerebellar vermis, with fusion of the cerebellar hemispheres and abnormally oriented folia. Supratentorial anomalies were also seen. Received: 26 April 1999 Accepted: 13 July 1999     

Dural enhancement in pituitary macroadenomas

We describe the normal dural enhancement patterns of the sellar region and determine whether the duramater is affected by pituitary macroadenomas. Dural enhancement appeared to be usually abnormal in 20 patients with pituitary macroadenoma compared with 20 control patients, mainly at the planum sphenoidale and carotid sulcus. However dural changes are subtle and their recognition requires knowledge of the normal enhancement patterns. Dural changes, reported in a variety of inflammatory and infectious dural diseases and after surgery, are not specific and may be also seen in pituitary macroadenomas. Received: 12 December 1998 Accepted: 3 November 1999     

Delayed transient neurologic toxicity due to tacrolimus: CT and MRI

We report a case of transient neurologic toxicity secondary to tacrolimus. The clinical and imaging findings are reported and their subsequent regression after interruption of therapy in the patient following a bone-marrow transplant is also described. The etiology of the neurotoxicity and its analogy with other immunosuppressant agents are discussed. Received: 18 June 1999/Accepted: 14 December 1999     

Diagnosing CADASIL using MRI: evidence from families with known mutations of Notch 3 gene

Clinical data and MRI findings are presented on 18 subjects from two families with neuropathologically confirmed CADASIL. DNA analysis revealed mutations in exon 4 of Notch 3 gene in both families. All family members with mutations in Notch 3 gene had extensive abnormalities on MRI, principally lesions in the white matter of the frontal lobes and in the external capsules. Of several family members in whom a diagnosis of CADASIL was suspected on the basis of minor symptoms, one had MRI changes consistent with CADASIL; none of these cases carried a mutation in the Notch 3 gene. MRI and clinical features that may alert the radiologist to the diagnosis of CADASIL are reviewed. However, a wide differential diagnosis exists for the MRI appearances of CADASIL, including multiple sclerosis and small-vessel disease secondary to hypertension. The definitive diagnosis cannot be made on MRI alone and requires additional evidence, where available, from a positive family history and by screening DNA for mutations of Notch 3 gene. Received: 17 February 1999 Accepted: 23 July 1999     

Cavernous dilatation of mesencephalic Virchow-Robin spaces with obstructive hydrocephalus

We describe two patients with mild ventricular dilatation, shown to have cystic spaces in the midbrain, which we interpreted as greatly enlarged Virchow-Robin spaces. We discuss the pathophysiology and the possible relations to the mild hydrocephalus. Received: 1 September 1999/Accepted: 22 October 1999     

Contrast enhancement of the cerebrospinal fluid on MRI in two cases of spirochaetal meningitis

We report two patients with meningitis due to spirochaetal infection, both of whom showed diffusely enhancing meninges around the brain and spinal cord. In addition, there was enhancement of the cerebrospinal fluid after intravenous administration of Gd-DTPA. Received: 1 March 1998/Accepted: 21 August 1999