Michiyuki Hayashi

Circulatory collapse and sudden death in respirator-dependent amyotrophic lateral sclerosis

Circulatory collapse and sudden death was defined retrospectively as one of the major critical problems among 23 respirator-dependent patients with amyotrophic lateral sclerosis (ALS). Six cases died from sudden cardiac arrest or anoxic encephalopathy following the circulatory collapse. In five among the six cases, sudden death or cardiac arrest occurred during sleep at night. Eight cases had had episodes of marked fluctuation of blood pressure before death, including paroxysmal elevation of blood pressure and heart rate, and successive sudden pressure fall without compensatory tachycardia. The spells of hypotension often occurred during sleep. In addition, the prospective study of diurnal variation of blood pressure, heart rate, plasma norepinephrine and plasma renin activity in nine respirator-dependent ALS patients showed continuous tachycardia and more remarkable nocturnal decrease of blood pressure compared with the control subjects. Plasma norepinephrine levels were constantly higher in the ALS patients particularly in a daytime. These indicate the continuous sympathetic hyperactivity in ALS. We discuss the cause of the circulatory collapse and sudden death in the respirator-dependent ALS patients in terms of the autonomic dysregulatory mechanism or the sympathetic hyperactivity.

Cytoplasmic and nuclear polyglutamine aggregates in SCA6 Purkinje cells

Aggregations of the alpha1A-calcium channel protein have been previously demonstrated in spinocerebellar ataxia type 6 (SCA6). Here the authors show that small aggregates, labeled by a monoclonal antibody 1C2 that preferentially detects expanded polyglutamine larger than that in SCA6 mutation, are present mainly in the cytoplasm but also in the nucleus of Purkinje cells. Although the length of expansion is small in SCA6, the current finding might indicate that SCA6 conforms to the pathogenic mechanism(s) in other polyglutamine diseases.

Autonomic failure in ALS with a novel SOD1 gene mutation

Article abstract The authors report a patient with ALS and a novel SOD1 gene mutation who was in the totally locked-in state and developed autonomic failure followed by sudden cardiac arrest. A neuropathologic study showed widespread multisystem degeneration, including involvement of the autonomic nuclei in the medulla and spinal cord. SOD1 gene analysis detected a missense mutation of V118L in exon 4. These findings show notable phenotypic heterogeneity for SOD1-associated ALS.

Distinct characteristics of amyloid deposits in early- and late-onset transthyretin Val30Met familial amyloid polyneuropathy

Late-onset transthyretin Val30Met-associated familial amyloid polyneuropathy (FAP ATTR Val30Met) cases unrelated to endemic foci in Japan show different clinicopathological features from the conventional early-onset cases in endemic foci. We compared the characteristics of amyloid deposits in early-onset FAP ATTR Val30Met cases in endemic foci and late-onset cases in non-endemic areas. Amyloid deposits in three early-onset cases from endemic foci and five late-onset cases from non-endemic areas were systematically examined post-mortem. Amyloid deposits in early-onset cases were highly congophilic and showed strong apple-green birefringence with Congo red staining and had long, parallel fibrils in most organs. On the other hand, those in late-onset cases were generally weakly congophilic and showed faint apple-green birefringence with Congo red staining and had short, haphazard fibrils. In the renal glomus and adrenal gland of early-onset cases, the characteristics of amyloid deposits were similar to those observed in late-onset cases. Analysis of cardiac amyloid using surface enhanced desorption/ionization time-of-flight mass spectrometry indicated that most transthyretin (TTR) was variant in early-onset cases, while more than half was composed of wild-type TTR in late-onset cases. Although characteristics of amyloid deposits may differ among individual organs of respective cases, especially in early-onset cases, the pattern was distinct between early- and late-onset cases. Amyloid deposition in late-onset cases may be similar to that observed in senile systemic amyloidosis with wild-type TTR deposition, suggesting that aging may play an important role in these cases.

Loss of large myelinated nerve fibres of the recurrent laryngeal nerve in patients with multiple system atrophy and vocal cord palsy.

OBJECTIVES: Vocal cord palsy seen in some patients with multiple system atrophy may result from neuronopathy of the recurrent laryngeal nerve. METHODS: Six controls and six patients with multiple system atrophy, four with and two without vocal cord palsy were studied. The number of myelinated nerve fibres were counted and fibre diameter histograms were established for the motor and sensory divisions of the laryngeal branch of the recurrent laryngeal nerve. RESULTS: Although both groups of patients with multiple system atrophy showed selective loss of the myelinated fibres in the motor branch, the change was greater in those with vocal cord palsy than in those without. The small myelinated nerve fibres (diameter < 7 microm) were decreased in number in both multiple system atrophy groups, whereas the large myelinated nerve fibres (diameter < 8 microm) were decreased only in those with vocal cord palsy, and preserved in those without the symptom. CONCLUSION: In multiple system atrophy, the small myelinated fibres innervating the vocal cord are affected first, without obvious clinical signs. The patient develops vocal cord palsy only after the loss of the large myelinated fibres, which mostly comprise the alpha motor axons that innervate the intrinsic laryngeal muscles.

Inflammatory demyelinating polyradiculitis in a patient with acute disseminated encephalomyelitis (ADEM).

A patient with severe acute disseminated encephalomyelitis died 12 days after the first symptom. Necropsy showed widespread severe demyelination in the CNS and some foci of demyelination in the spinal roots. The lesions in the peripheral nervous system were characterised by myelin stripping and the presence of macrophages, being severest in the spinal nerve roots. Some axons were completely demyelinated, whereas the axons themselves were preserved. Pathologically established ongoing demyelination in both CNS and peripheral nervous systems raises the possibility of a shared pathological epitope.

Decrease of medullary catecholaminergic neurons in multiple system atrophy and Parkinson's disease and their preservation in amyotrophic lateral sclerosis

We investigated the number of tyrosine hydroxylase (TH)-immunoreactive neurons in the C1 and A2 regions of the medulla, the sites of the baroreflex arc, in 7 patients with multiple system atrophy (MSA), 8 with Parkinsons disease (PD), 9 with amyotrophic lateral sclerosis (ALS), and 12 age-matched normal subjects to analyze the relationship between cardiovascular dysfunction and medullary catecholaminergic neurons. Orthostatic hypotension (OH) was marked in all the MSA patients and moderate in three PD patients. Three of the five ALS patients who had been on respirators showed lability of blood pressure; paroxysmal hypertension and nocturnal hypotension without compensatory tachycardia. All the MSA patients showed extremely marked decrease of TH-immunoreactive neurons in both the C1 and A2 regions. In the patients with Parkinsons disease, numerous TH-immunoreactive neurons contained Lewy bodies that were immunostained by antibody to TH. TH-immunoreactive neurons were decreased very markedly in the A2 regions of two patients with OH, and three patients without OH showed fairly marked decreases in the C1 or A2 region. In contrast, the number of TH-immunoreactive neurons in ALS was the same as in normal subjects. In MSA and some PD patients, orthostatic hypotension may partly be due to the involvement of the medullary catecholaminergic neurons. The lability of blood pressure in ALS probably is not related to the medullary catecholaminergic neurons.

Hyposensitivity of peripheral α-adrenoceptors in respiratordependent amyotrophic lateral sclerosis assessed by intravenous norepinephrine infusion

Intravenous norepinephrine infusion test was performed in eight patients with amyotrophic lateral sclerosis (ALS) supported by respirators and nine control subjects, to examine α-adrenoceptor function of peripheral resistant blood vessels. Baseline plasma norepinephrine concentrations in ALS patients were significantly higher than those in control subjects, indicating basal sympathetic hyperactivity (normal 218.2 ± 59.7 pg/ml; ALS 450.0 ± 288.4 pg/ml). The stimulus-response curves in the patients were similar to those in control subjects, and there were no significant differences between mean gains of the stimulus—response curves in both groups (normal 18.7 ± 5.5; ALS 15.2 ± 11.2). However, three ALS patients, two of whom had circulatory fluctuation and sympathetic hyperactivity, revealed lower gain levels than the mean minus 2 SD in control subjects (4.7, 1.1 and 3.7). This indicates hyposensitivity or down-regulation of the α-adrenoceptor function of peripheral blood vessels in these ALS patients. For early detection of sympathetic hyperactivity and prediction of circulatory collapse, it would be useful to measure the plasma norepinephrine concentration and the gain of the norepinephrine infusion curve in respirator-dependent ALS patients.

Autonomic dysfunction and orthostatic hypotention caused by vitamin B12 deficiency

Orthostatic hypotension sometimes is a reversible neurological complication of vitamin B12 deficiency.1 2 Eisenhofer detected deficient sympathetic catecholamine release in insulin tolerance testing,2 but the mechanism of orthostatic hypotension in vitamin B12 deficiency remains unclear. We report a patient with vitamin B12 deficiency and reversible orthostatic hypotension, and discuss the mechanism of this symptom. A 77 year old man admitted to our hospital had had unstable gait and urinary urgency for 6 months, clumsiness of the hands and tingling sensations in the legs for 3 months, and, for a month, occasional dizziness on standing. The dizziness was mild without any attack of syncope. He had no other symptoms or signs of autonomic dysfunction but impotence and erectile failure were noted 10 years before the onset of neurological symptoms. He had not taken any medicine which would affect the autonomic nervous system. He did not have a habit of drinking. Physical examination on admission detected no signs of anaemia, heart failure, or dehydration. …

Autonomic dysfunction in Machado-Joseph disease assessed by iodine123-labeled metaiodobenzylguanidine myocardial scintigraphy

Iodine123-labeled metaiodobenzylguanidine, a radioiodinated analogue of norepinephrine, is a tracer for evaluating sympathetic function. We used iodine123-labeled metaiodobenzylguanidine myocardial scintigraphy and sympathetic skin response to study autonomic nervous functions in 19 patients with Machado-Joseph disease (MJD) and 20 control subjects. Planar imaging of all the participants was done to evaluate myocardial scintigraphy. The ratio of average counts in the heart to average counts in the mediastinum was calculated for both early and delayed images, the latter of which reflects the cardiac neural uptake of the tracer. Single photon emission computed tomography also was done on 12 patients with MJD to examine regional tracer uptake to the heart. The mean ratio of counts in the heart to counts in the mediastinum in the delayed images was lower for the patients with MJD than for the control subjects (p <0.01). Abnormal sympathetic skin response was present in 6 patients with MJD whose mean ratio of counts in the heart to counts in the mediastinum was lower than that of patients with MJD who had normal sympathetic skin response (p <0.01). A single photon emission computed tomography study showed significantly lower accumulation of the tracer in patients with MJD than in the control subjects in the anterior lateral sectors predominantly innervated by sympathetic nerves but not in the inferior septal sectors reported to be under main innervation by parasympathetic fibers. These results show that MJD is accompanied by cardiac sympathetic dysfunction, as detected by iodine123-labeled metaiodobenzylguanidine myocardial scintigraphy, which appears to be correlated with sudomotor sympathetic dysfunction.