Frontotemporal lobar degeneration with motor neuron disease showing severe and circumscribed atrophy of anterior temporal lobes.

Frontotemporal lobar degeneration (FTLD) is characterized by a variety of behavioral and psychiatric symptoms based on the dysfunction of frontal and/or temporal lobes. A 63-year-old Japanese man without a family history of neurological diseases developed progressive symptoms of frontotemporal dementia, followed by motor neuron disease (MND). Brain magnetic resonance images demonstrated severe atrophy in the anterior temporal lobes from early clinical stage. The symptoms got rapidly worsened and the patient died of respiratory failure 1year 8months after the disease onset. A postmortem study revealed severe and circumscribed atrophy in the anterior temporal lobes, and histological examination disclosed marked neuronal loss with many neuronal cytoplasmic inclusions which were immunoreactive for ubiquitin antibodies and phosphorylated TAR DNA-binding protein of 43kDa (TDP-43) antibodies in hippocampal dentate granule cells and amygdalae, as well as a few neuronal cytoplasmic inclusions without dystrophic neurites in the temporal neocortex. This case report showed typical features of FTLD-MND in clinical course and TDP-43 pathology with unusual severity and distribution of cerebral atrophy, suggesting a unique manifestation of FTLD-MND.

Coexistence of amyotrophic lateral sclerosis and argyrophilic grain disease: a non-demented autopsy case showing circumscribed temporal atrophy and involvement of the amygdala.

We report a case of a 68-year-old right-handed man with sporadic amyotrophic lateral sclerosis (ALS) and argyrophilic grain disease (AGD) having a 22-month duration. His initial symptoms were dysarthria and swallowing difficulty at the age of 67. Subsequently bulbar palsy and pyramidal signs developed. His cognitive functions including face recognition, personality, and behavior were not changed compared with that of before the disease onset. However, magnetic resonance imaging disclosed severe right side-predominant temporal atrophy. The neurological diagnosis was bulbar type ALS. Pathological examination disclosed histological evidence of ALS, including loss of Betz cells and lower motor neurons, corticospinal tract degeneration, and Bunina bodies. In addition, severe neuronal loss in the bilateral temporal cortex with an anterior gradient was found. Ubiquitin-positive inclusions were encountered in the spinal anterior horn cells and hippocampal dentate gyrus, while few ubiquitin-positive inclusions were noted in the affected temporal cortex. The amygdala, especially the basolateral nuclear group, was severely affected by neuronal loss with tissue rarefaction. Moderate neuronal loss was encountered in the parahippocampal gyrus, and to a lesser degree, in the ambient gyrus. Unexpectedly, many argyrophilic grains, coiled bodies, tau-positive bush-like astrocytes, pretangles, and ballooned neurons were found in the limbic system and temporal cortex. In the hippocampus, selective tau accumulation with minor neurofibrillary changes was observed in CA2 neurons. The present case suggests that (i) ALS and AGD do rarely coexist, and (ii) when ALS patients have severe temporal atrophy, not only ALS with dementia but also concurrent AGD should be considered in the differential diagnosis.

Electrophysiological evaluation of conduction in the most proximal motor root segment.

Root conduction time (RCT), defined as the time difference between M-wave latency by cervical magnetic stimulation (CMS) and the total peripheral motor conduction time calculated from the shortest F-wave latency, was investigated in patients with inflammatory demyelinating neuropathies (IDP) and amyotrophic lateral sclerosis (ALS). The minimal threshold for CMS also was studied. In the IDP patients, conduction in the proximal motor root segment was considered abnormal in 52% by the RCT and in 47% by the minimal threshold for CMS, whereas both were normal in 85% of the ALS patients. These findings suggest that the RCT and minimal threshold for CMS might be additional parameters for evaluating motor nerve conduction in IDP.