Increased number of astrocytes and macrophages/microglial cells in the corpus callosum in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by degeneration of both upper and lower motor neurons. Neuropathologically, degeneration of the corticospinal tracts is evident and may be associated with loss of motor neurons in the motor cortex. The data from a recently developed imaging technology, the diffusion tensor imaging method of MRI have suggested that white matter in the corpus callosum (CC) is lost in patients with ALS. However, the specific neuropathologic changes of the commissural fibers remain unclear. To investigate the pathologic changes of the CC in ALS, we analyzed midsagittal sections of the CC from eight individuals with ALS and eight controls by using conventional staining and immunohistochemistry with antibodies against CD68, GFAP and phosphorylated neurofilament (SMI-31). The CC was divided into seven areas. The number of CD68-immunoreactive macrophages/microglia and GFAP-immunoreactive astrocytes was significantly higher in individuals with ALS than in controls in all areas of the CC except the rostrum. Among the patients with ALS, the number of macrophages/microglia and astrocytes was significantly higher in the posterior midbody and isthmus than in the rostrum. There was no significant difference in number of SMI-31 immunoreactive axons between ALS and control group as well as among each area of the CC. These findings suggest that pathologic changes in the CC in ALS are present in the posterior midbody and isthmus, where callosal motor fibers may traverse between the two hemispheres. CD68 and GFAP immunohistochemistry are sensitive methods to detect those pathologic changes in routine paraffin-embedded specimens.

Neuropathologic analysis of Lewy-related α-synucleinopathy in olfactory mucosa.

We analyzed the incidence and extent of Lewy-related α-synucleinopathy (LBAS) in the olfactory mucosa, as well as the central and peripheral nervous systems of consecutive autopsy cases from a general geriatric hospital. The brain and olfactory mucosa were immunohistochemically examined using antibodies raised against phosphorylated α-synuclein. Thirty-nine out of 105 patients (37.1%) showed LBAS in the central or peripheral nervous systems. Seven patients presented LBAS (Lewy neurites) in the olfactory lamina propria mucosa. One out of the seven cases also showed a Lewy neurite in a bundle of axons in the cribriform plate, but α-synuclein deposits were not detected in the olfactory receptor neurons. In particular, high incidence of α-synuclein immunopositive LBAS in the olfactory mucosa was present in the individuals with clinically as well as neuropathologically confirmed Parkinson's disease and dementia with Lewy bodies (6/8 cases, 75%). However, this pathologic alteration was rare in the cases with incidental or subclinical Lewy body diseases (LBD) (one out of 31 cases, 3.2%). In the olfactory bulb, the LBAS was usually present in the glomeruli and granular cells of most symptomatic and asymptomatic cases with LBD. Our studies further confirmed importance of the olfactory entry zone in propagation of LBAS in the human aging nervous system.

[Three cases of cervical epidural hematoma mimicking acute ischemic stroke].

We report 3 cases of spontaneous cervical epidural hematoma with sudden onset of neck pain followed by the development of unilateral limb weakness. All of the patients were initially suspected to have acute ischemic stroke. We considered using intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) to treat 2 of the 3 patients who had arrived at our hospital within 2 hours of the symptom onset. However, we did not administer rt-PA therapy to these patients because the symptoms were mild. We treated all 3 patients with other antithrombotic drugs until the diagnosis of cervical epidural hematoma was confirmed. Patients with spontaneous cervical epidural hematoma usually present with acute neck pain followed by the development of bilateral limb weakness and urine retention; unilateral limb weakness is rare. Patients with this uncommon presentation must be distinguished from stroke.