PRIMARY LATERAL SCLEROSIS: CLINICAL FEATURES, NEUROPATHOLOGY AND DIAGNOSTIC CRITERIA

TLDR

Clinical features were limited to dysfunction of the descending motor tracts, including spastic quadriparesis, pseudobulbar affect, spastic dysarthria, hyper‑reflexia, and bilateral Babinski signs. The study proposes diagnostic criteria for primary lateral sclerosis based on clinical, laboratory, and imaging features. Eight patients with a homogeneous syndrome of progressive symmetric spinobulbar spasticity were studied. Patients showed absent lower motor neuron signs, preserved cognition, median onset 50.5 yr, 19 yr disease duration, selective motor cortex loss of Betz cells, reduced pyramidal cell size, precentral gyrus atrophy on MRI, decreased pericentral glucose uptake on PET, and prolonged central motor conduction times.

Abstract

Eight patients with a homogeneous syndrome of progressive symmetric spinobulbar spasticity were studied. Clinical features were limited to those associated with dysfunction of the descending motor tracts and included spastic quadriparesis, pseudobulbar affect, spastic dysarthria, hyper-reflexia and bilateral Babinski signs. Lower motor neuron findings were absent and higher cognitive function preserved. Median age of onset was 50.5 yrs and median disease duration was 19 yrs Neuropathologic features (including morphometric analysis) in the single autopsied case confirmed the selective involvement of the motor cortex. There was complete absence of Betz cells from layer 5 of the precentral cortex and the remaining pyramidal cells were significantly smaller than those seen in normal controls. Magnetic resonance imaging (MRI) revealed atrophy of the precentral gyrus and positron emission tomography (PET) scans showed diminished glucose [18F]flurodeoxyglucose uptake in the pericentral cortex. Magnetic motor cortex stimulation revealed markedly prolonged central motor conduction times. The literature is reviewed and diagnostic criteria for primary lateral sclerosis based on clinical, laboratory and imaging features are proposed