Reid R. Heffner

Primary malignant lymphomas of the central nervous system

Eighty‐three cases of primary malignant lymphomas of the central nervous system (CNS) from the files of the AFIP were studied according to various clinical and pathologic parameters. The histologic patterns observed are analogous to those seen in the spectrum of malignant lymphomas arising in the reticuloendothelial system of other organs. The authors favor the diagnosis of primary malignant lymphoma of the CNS rather than that of “reticulum cell sarcoma” or “microgliomatosis” used in the past. Lesions are frequently multifocal, and surgery, other than for diagnostic biopsy, is not usually beneficial. The clinical course can be significantly prolonged by radiation therapy.

An eye movement disorder in amyotrophic lateral sclerosis.

Defective pursuit eye movements were recorded by electrooculography (EOG) in 11 of 18 patients (61%) with amyotrophic lateral sclerosis. Pursuit defects consisted of a breakdown of smooth tracking into saccadic motions that were grossly in excess (frequencies and amplitudes) of saccadic interruptions of pursuit in normal subjects. In nine patients, defective pursuits (cogwheeling) were obvious by visual inspection as well as by EOG; in two, this abnormality was seen only by EOG. In eight patients, the pursuit defect was the only abnormality of oculomotor function; in three, there were also saccadic defects (optokinetic nystagmus or conjugate gaze) discerned by EOG. Autopsy revealed neuronal degeneration in substantia nigra and demyelination in internal capsule in one patient with the pursuit defect but not in another patient without the defect. The pursuit defect may be a sign of extrapyramidal or supratentorial pyramidal involvement in ALS.

Prognostic factors in brainstem gliomas

Although brainstem gliomas carry the worst prognosis of any brain tumor in children, with median survivals of 9 to 12 months, there may be a subgroup of long-term survivors. We have identified 12 children with brainstem gliomas, 5 of whom have survived > 6 years and 6 ≤ 12 months. Another child, alive and well 3 years following diagnosis, was considered in the long-term survivor group. Favorable prognostic factors included neurofibromatosis, symptoms ≥ 12 months before diagnosis, calcification on CT, exophytic location, and pathology suggesting a low-grade tumor. Recognition that certain patients with brainstem gliomas may have prolonged survivals even in the absence of definitive treatment must be taken into consideration when new treatment regimens are being formulated.

Selective paralysis of downward gaze caused by bilateral lesions of the mesencephalic periaqueductal gray matter

A patient who had selective paralysis of downward gaze caused by bilateral lesions of the dorsolateral mesencephalic periaqueductal gray (PAG) matter is reported. Her necropsy findings differed from all previous reports of the syndrome, in that regions of the mesencephalon that have been considered as critical for executing downward gaze (dorsomedial to red nuclei, rostral interstitial nuclei of the medial longitudinal fasciculus [ri MLF]) were normal. These lesions may have produced the syndrome by involving the caudal portions of the nuclei of the posterior commissure (subcommissural), from which one of the commissural systems used by the ri MLF originates. It is also possible that the syndrome was produced by selective destruction of PAG neurons that generate downward impulses or by interruption of posterior commissure fibers containing downward impulses that travel through the dorsolateral PAG before terminating in the more ventral mesencephalon.