Kenji Onouchi

Cardiovascular dysautonomia in de novo Parkinson's disease

BACKGROUND Clinical symptoms of Parkinsons disease (PD) include not only motor distress, but also autonomic dysfunction. OBJECTIVE To clarify the progression of autonomic nervous dysfunction in PD. METHODS The subjects were 44 patients with de novo PD. Autonomic nervous function, including cardiac sympathetic gain, was evaluated on the basis of cardiac radioiodinated metaiodobenzylguanidine (MIBG) uptake, the response to the Valsalva maneuver, and spectral analyses of the RR interval and blood pressure. RESULTS Decreased cardiac MIBG uptake was found even in patients with early stage PD. MIBG uptake gradually decreased with increased disease severity. Hemodynamic studies using the Valsalva maneuver revealed that patients with early stage PD had reduced baroreceptor reflex sensitivity (BRS) in phase II, but not phase IV. Blood pressures normally rose in phases II and IV, but the increments decreased with disease progression. In early stage PD, the low frequency power of the RR interval (RR-LF) and the ratio (LF/HF) of RR-LF to the high frequency component of the RR interval (RR-HF) were significantly lower than the respective control values, despite no significant difference in RR-HF; these variables decreased with disease progression. CONCLUSION Our results show that latent sympathetic nervous dysfunction without parasympathetic dysfunction, especially that involving the sinus node, is already present in early stage de novo PD. It is unclear whether the responsible lesion is central or peripheral.

Cardiovascular autonomic dysfunction in dementia with Lewy bodies and Parkinson's disease

OBJECTIVE We estimated the extent and pattern of cardiovascular autonomic dysfunction in dementia with Lewy bodies (DLB) as compared with that in Parkinsons disease (PD). METHODS We performed meta-iodobenzylguanidine ((123)I-MIBG) scintigraphy of the heart and hemodynamic autonomic function testing using the Valsalva maneuver in 27 patients with DLB, 46 with PD, and 20 controls. RESULTS (123)I-MIBG uptakes in DLB were reduced as compared with those in control and PD. Hemodynamic studies revealed that DLB had decreased baroreceptor reflex and reduced responses of SBP in phases II and IV as compared with PD and control. SBP responses on standing and the difference in plasma norepinephrine (NE) concentrations between supine and standing positions were reduced in PD as compared with those in control. Furthermore, SBP responses on standing, plasma NE concentrations in supine and standing positions, and the difference in plasma NE concentrations between these positions were significantly lower in DLB than in PD and control. Plasma NE concentrations in DLB with orthostatic hypotension (OH) were lower than that in DLB without OH, although some patients who had DLB with orthostatic hypotension had relatively normal plasma NE levels. CONCLUSION Cardiovascular autonomic dysfunction is more severe in DLB than in PD and is usually caused by the loss of postganglionic sympathetic nervous function, although dysautonomia in some patients with DLB may result from preganglionic dysfunction.

A case of amusia caused by the infarction of anterior portion of bilateral temporal lobes.

It remains an unsettled question which brain regions participate in music perception. During singing a familiar song, the retrieval from long-term memory is necessary, but the mechanism of that retrieval is still unclear. We carried out a detailed examination of musical ability in a patient with amusia and control subjects and identified the lesion sites of our patient using MRI. Compared with controls, the patient manifested the following impairments in music perception: (i) the recognition and discrimination of familiar melodies; (ii) the discrimination of unfamiliar phrases; (iii) the discrimination of isolated chords. During singing familiar nursery songs, the patient showed the replacement of one phrase of the melody. In MRI, the patient had old infarction in the anterior portion of the temporal lobes bilaterally. In conclusion, the anterior temporal lobes participate in the perception and expression of music. During singing, the song is retrieved from long-term memory by a unit of one phrase. The dysfunction of that retrieval caused the replacement of the succeeding phrases of the original with the wrong tune, and we named this phenomenon paramelodia.

Impaired cardiovascular autonomic function in Parkinson's disease with visual hallucinations.

We assessed the relations of visual hallucinations (VH) to cardiovascular autonomic dysfunction in patients with Parkinsons disease (PD). The subjects were 37 patients without VH (VH(−)) and 31 with VH (VH(+)). Autonomic function was evaluated on the basis of cardiac 123‐radioiodinated metaiodobenzylguanidine (123I‐MIBG) uptake and hemodynamic testing with Valsalva maneuver. Systolic blood pressure (SBP) and plasma norepinephrine concentrations (NE) were measured by tilt‐table testing. 123I‐MIBG uptake was lower in VH(+) than VH(−). Hemodynamic studies showed that VH(−) had only cardiac sympathetic and parasympathetic dysfunction, while VH(+) additionally had reduced vasomotor sympathetic functions. The fall in SBP during tilt‐table testing was greater in VH(+) than VH(−). NE and its difference in the supine and upright positions were decreased in VH(+). We conclude that cardiac and vasomotor sympathetic dysfunction is more severe in VH(+) than in VH(−). Severe dysfunction in PD with VH is probably attributed to Lewy‐body lesions or neuronal loss in sympathetic ganglia, the central autonomic system, or both.

Cardiovascular dysautonomia in Parkinson's disease and multiple system atrophy

Objectives - To determine whether Parkinsons disease (PD) can be distinguished from multiple system atrophy (MSA) on the basis of the assessment of iodine-123 meta-iodobenzylguanidine ( 123 I-MIBG) radioactivity in heart and cardiovascular autonomic function. Patients and methods - Seventeen patients with MSA, 39 with PD, and 25 healthy volunteers underwent 123 I-MIBG scintigraphy and hemodynamic autonomic function tests using Valsalva maneuver (VM). Baroreceptor reflex sensitivity (BRS) was measured using the slope of the relation between RR interval and blood pressure during the fourth phase. Results - 123 I-MIBG radioactivity in heart of patients with PD was lower than that of control subjects and patients with MSA, but there was some overlap between PD and MSA. BRS in patients with PD who had a 123 I-MIBG radioactivity similar to that in MSA was larger than that in patients with MSA, with no overlap in any patient. Conclusion - Assessment of BRS may be useful for differentiating between MSA and PD that had a 123 I-MIBG radioactivity similar to MSA.

Cardiovascular dysautonomia in Parkinson's disease and multiple system atrophy [This article has been retracted]

Objectives –  To determine whether Parkinsons disease (PD) can be distinguished from multiple system atrophy (MSA) on the basis of the assessment of iodine‐123 meta‐iodobenzylguanidine (123I‐MIBG) radioactivity in heart and cardiovascular autonomic function.

Bax-induced apoptosis not demonstrated in the congenital toxoplasmosis in mice

A prominent neuropathological change observed in a murine model of congenital toxoplasmosis is cerebral cortical hypoplasia. In the early embryonic life of toxoplasmosis mice, the number of apoptotic cell observed in cerebral cortex is increased, indicating that increased number of apoptotic cells might relate to the pathogenetic mechanism of the cortical hypoplasia. Immunohistochemical expression of apoptosis-related factors, Bcl-2 and Bax has been studied in fetal murine brains infected with toxoplasma and in controls. Paraffin sections of the fetal brains on embryonic day (ED) 10, 12, 14, 16 and 18 were applied for the immunostains of Bcl-2 and Bax. Totally, 47 experimental animals (ED10: n=8, ED12: n=6, ED14: n=12, ED16: n=6, ED18: n=15) and 48 control animals (ED10: n=6, ED12: n=8, ED14: n=9, ED16: n=9, ED18: n=16) were examined. Bcl-2 positive cells were detected on ED10, whereas Bax positive cells appeared on ED14. No difference of Bcl-2 and Bax expression between toxoplasmosis and control groups was detected, suggesting that there is no clear relation between Bax-induced apoptosis and cortical dysplasia in congenital toxoplasmosis.

Actions anchored by concepts: Defective action comprehension in semantic dementia

Objective: To study the ability of patients with semantic dementia to understand actions, in order to examine the contribution of semantic memory to action comprehension. Methods: The ability to comprehend symbolic and instrumental actions was assessed in 6 patients with semantic dementia and 10 healthy controls. The patients were also given the imitation test of meaningful and meaningless actions. Results: In all patients with semantic dementia, comprehension of both symbolic and instrumental actions was defective. The comprehension of symbolic actions was more impaired than that of instrumental actions. Their ability to imitate other’s actions was well preserved. Conclusion: This study showed that comprehension of action was impaired in semantic dementia, suggesting that semantic memory has an important role in comprehension of human action.

Somatosensory and skin temperature disturbances caused by infarction of the postcentral gyrus

Abstract. Somatosensory functions are subdivided into 2 large groups: the elementary somatosensory functions, which consist of light touch, pain, thermal sensation, joint position sense, and vibration sense, and the intermediate somatosensory functions, which include 2-point discrimination, tactile localization, weight, texture, and shape perception. In this report, we describe a patient with somatosensory dysfunction after infarction of the postcentral gyrus. On physical examination a month after the onset of the infarction, voluntary movements were skilful, and both the elementary and intermediate somatosensory functions were disturbed in the right hand. The patient also displayed a decrease in the skin temperature of the right hand. The sensory-evoked potential in response to electrical stimulation of the right median nerve was normal, and brain MRI showed that the infarction was located in the posterior half of the left postcentral gyrus. These findings suggested that the lesion was situated at areas 1 and 2, and that area 3b was preserved. Thermography revealed that the skin temperature of the right hand was decreased predominantly on the ulnar side, and that recovery from cooling with ice water was delayed. By comparing the results of our patient with a case report that showed no disturbance of the elementary somatosensory functions with a localized lesion in the postcentral gyrus, we suggest that area 1 participates in the elementary somatosensory functions and that skin temperature may be controlled somatotopically in the somatosensory cortex.

P35.25 Visual hallucination and cardiovascular autonomic dysfunction in Parkinson’s disease

complication of surgical treatment of bilateral chemodectoma, and the usefulness of this method to assess patients with autonomic storm. Patient and methods: A 27-year-old man had surgical resection of bilateral giant carotid body chemodectomas. Immediately after the second procedure he developed paroxysmal hypertension, severe headaches, vomiting and dysphagia. Baroreceptor sensitivity was measured with a computer system during continuous non-invasive blood pressure monitoring. Results: The methods were well tolerated during autonomic storm. Baroreflex sensitivity was 3.73 ± 2.31 ms/ mmHg (normal values: 8.41–10.62 in 70 controls). Conclusion: Baroreceptor sensitivity can be easily used in a patient during autonomic storm to assess carotid body denervation.