A case of motor neuron disease with clinical and pathological resemblance to amyotrophic lateral sclerosis (ALS) in a woman who was severely bitten on the ankle by a cat is described. Weakness first appeared at the ankles and relentlessly advanced proximally, terminating in death from pulmonary failure in a year. A number of unusual features that are uncharacteristic of ALS were found that included a markedly elevated antinuclear antibody titre in the serum and the presence of prominent oligoclonal bands in the cerebrospinal fluid. The spinal cord showed loss of anterior horn cells and pyramidal degeneration that are characteristic of ALS, but an extraordinary finding was the presence of transmural granulomatous inflammation of numerous small and medium sized vessels, especially veins, in the subarachnoid space around the cord. There were also inflammatory changes in the brainstem and spinal cord consisting of microglial and astrocytic nodules and perivenous cuffing by mononuclear cells. Ill-defined hyaline eosinophilic cytoplasmic inclusions were seen in some remaining anterior horn cells. No viral particles were found by electron microscopy despite an extensive search. Virological studies were inconclusive but there is reason to believe that this patient's illness was caused by an as yet unidentified virus.

A 35-year-old woman who died after a long history of an illness consistent with Shwachman-Diamond Syndrome, was found to have extensive calcified necrotizing lesions confined to the pontocerebellar fibers of the basis pontis. The possible relationship of this recently described lesion to the patient's immunosuppressed state and/or other systemic metabolic disturbances is discussed.

Neuropathological findings from 39 acquired immune deficiency syndrome (AIDS) autopsies of primarily neurologically symptomatic patients and 7 brain biopsies from AIDS patients performed at St. Paul’s Hospital, Vancouver, British Columbia are reported. Autopsy findings included human immunodeficiency virus-1 (HlV)-type multinucleated giant cell (MNGC)-associated encephalitis seen in 17 patients, toxoplasmosis in 7 patients, and cytomegalovirus encephalitis and/or microglial nodule-associated nuclear inclusions in brain parenchyma in 9 patients. Central nervous system lymphoma was identified in 11 autopsy patients and in 4 of 7 brain biopsies. Infectious processes including HIV encephalitis were seen in 10 of 11 autopsied patients with lymphoproliferative lesions in the brain parenchyma, while 40% of patients without lymphoma had HIV-type MNGC or opportunistic infections. CNS lymphoma was not significantly increased in incidence in patients with a clinical history of zidovudine treatment, but increased duration of survival after the diagnosis of AIDS was associated with increased incidence of lymphoma in both untreated and zidovudine-treated patients. Patients displaying HIV MNGC within microglial nodules had a shorter mean duration of survival after diagnosis of AIDS than those patients with HIV encephalitis with dispersed MNGC, white matter vacuolation, and gliosis.

The current evidence for and against abnormalities of the blood-brain barrier in “normal” aging and Alzheimer's disease is reviewed. Recent studies of cerebral amyloid angiopathy, a microangiopathy commonly observed in Alzheimer's disease and one suggested to result from blood-brain barrier derangement, are discussed with particular attention to the biochemical nature of the vascular amyloid material, and features it shares with the amyloid found in senile plaque cores and with neurofibrillary tangles. Modern techniques that will probably clarify blood-brain barrier pathophysiology are reviewed.

We describe a unique case of chronic lymphocytic leukemia (CLL) in a patient who presented with bitemporal hemianopsia, adrenal insufficiency, and gonadotrophin deficiency. Studies revealed an enhancing intrasellar mass with suprasellar extension and displacement of the optic chiasm. Peripheral blood and cerebrospinal fluid (CSF) studies disclosed a monoclonal IgM kappa expressing B-cell CLL. Biopsy of the pituitary mass revealed dense infiltration of the pituitary gland by leukemic cells. This is, to our knowledge, the first reported case of CLL presenting as a pituitary mass lesion.

This mini-review will summarize some of the major contributions of Neuropathology to understanding the structural basis of several forms of intractable epilepsy. Because of space limitations, only selected morphologically defined brain abnormalities will be considered and illustrated. By definition, the types of specimen encountered by Neuropathologists are those resected to treat intractable seizure disorders. One can therefore infer that the 'lesions' encountered in some way caused or at least contributed to the epilepsy, though the leap from observed neuropathologic abnormalities to 'seizuregenesis' is not always straightforward—indeed often is very tortuous and obscure. Nevertheless, a Neuropathologist working with a team of neurologists, neurosurgeons, electrophysiologists, neuropsychologists, and others, can contribute to a richer understanding of why seizures are triggered within human brain tissue, and therefore how they may be more effectively treated.