Sequential imaging analysis using MIBG scintigraphy revealed progressive degeneration of cardiac sympathetic nerve in Parkinson's disease.

BACKGROUND: Metaiodobenzylguanidine (MIBG) cardiac scintigraphy was used to differentiate Parkinson's disease (PD) with Lewy body pathology from other degenerative parkinsonisms. MIBG cardiac scintigraphy demonstrates the extent of degeneration of myocardial post-ganglionic sympathetic nerves in patients with PD. Because of its specificity for Lewy body (LB) pathology, MIBG scan might also be useful biomarker for the neurodegeneration attributed to PD. To estimate the utility of the imaging technique as a biomarker, we conducted sequential imaging analysis and power analysis. METHODS: Sixty-three patients who met the UK PD Society Brain Bank criteria were enrolled in this study. (123) I-MIBG myocardial scintigraphy was performed on all subjects, and the heart to mediastinum (H/M) ratio was calculated. A second imaging session was carried out after a mean interval of 268 days. RESULTS: Sequential imaging revealed a 2.9% decline of the H/M ratio from the baseline to the follow-up image, which reached statistical significance, but the power analysis showed that a relatively large number of patients would be required to demonstrate the neuroprotective effects of any therapy. CONCLUSIONS: Sequential imaging using (123) I-MIBG myocardial scintigraphy revealed progressive degeneration of the cardiac sympathetic nerve in 63 patients with PD. Although careful elimination of other disease conditions that damage the cardiac sympathetic nerve system is necessary, (123) I-MIBG myocardial scintigraphy may be a useful addition to clinical trials that intend to prove neuroprotection among patients with PD.

Evidence for brainstem structures participating in oculomotor integration.

The cerebellar flocculus has been implicated in vestibulo-oculomotor control. One major central input to this structure originates from brainstem cells in the paramedian tract (PMT), whose function is unknown. Here it is reported that PMT cells in the pons carry vestibular and eye movement signals and their pharmacological inactivation produces a leaky integrator combined with vestibular imbalance. The results suggest that PMT cells provide the cerebellum with sensory and motor signals that are essential for velocity-to-position integration, a common premotor process that is required in all motor systems.

Clinical, neuropathological, and molecular study in two families with spinocerebellar ataxia type 6 (SCA6).

To clarify the clinical, neuropathological, and molecular characteristics of spinocerebellar ataxia type 6 (SCA6), two unrelated Japanese families with SCA6 were studied. A clinical feature of the two families was late onset "pure" cerebellar ataxia. Pathologically, three SCA6 brains consistently showed Purkinje cell dominant cortical cerebellar degeneration. Morphometric analysis showed that loss of the cerebellar granule cells and inferior olivary neurons were very mild compared with the severity of Purkinje cell loss. There was no obvious ubiquitin immunoreactive nuclear inclusions. All affected patients had identical expanded alleles, and the expansion was also homogeneously distributed throughout the brain without mosaicism. The present study showed that SCA6 is characterised by Purkinje cell dominant cortical cerebellar degeneration, highly stable transmission of the CAG repeat expansion, and lack of ubiquitin immunoreactive nuclear inclusions.

Double filtration plasma exchange and immunoadsorption therapy in a case of stiff-man syndrome with negative anti-GAD antibody.

We report the effects of double filtration plasma exchange and immunoadsorption therapy which were performed for a case of stiff-man syndrome even though the patient was negative for anti-glutamic acid decarboxylase (GAD) antibody. The patient underwent a course of four double filtration plasma exchanges, which resulted in marked clinical improvement. Painful muscle cramps disappeared and muscle stiffness reduced within a day after the first plasma exchange. The patient's improvement continued, but his condition declined again about ten months after plasma exchange. Immunoadsorption therapy was then performed, and this treatment was also effective.

[A case of frontal gait apraxia caused by hypoxic encephalopathy].

We reported a rare case who had hypoxic-encephalopathy causing frontal apraxia of gait. The patient, a 34-year-old female, was admitted in July, 1994, complaining of difficulty in walking after anoxic brain damage caused by ventricular arrhythmia. She had difficulty in raising her feet, which appeared to be rooted to the floor. There was no evidence of motor paralysis, spasticity, rigidity or sensory loss, but she did show frontal lobe signs such as foot grasp reflex and Gegenhalten. Cranial MRI showed slight atrophy of the frontal lobe. On T2 weighted image, high-intensity areas were detected at the posterior internal capsule and corona radiata. Single photon emission CT (123I-IMP) demonstrated a low perfusion area which included the inferomedical part of the frontal lobe. After 8 months of hospitalization, her postural instability and unsteady gait slowly improved without treatment as frontal signs such as foot grasp reflex disappeared. We speculate that her apraxia of gait may result from grasp reflex and Gegenhalten.

[A case of potassium-sensitive periodic paralysis with cardiac dysrhythmia].

The authors reported a case of potassium-sensitive periodic paralysis with cardiac dysrhythmia. The patient was a 21-year-old male and had periodic paralysis and asymptomatic cardiac dysrhythmia since the age of 12. His attacks worsened in frequency and intensity which brought him to our hospital at the age of 21. Physical examination on admission revealed slight dysmorphic features such as hypoplastic mandible and high-arched palate. He had slight proximal muscle atrophy with no myotonia. Electrocardiogram showed multifocal ventricular arrhythmia. The serum potassium levels during his paralytic attacks were normal or slightly decreased (3.6-4.2 mEq/l). Both potassium and glucose tolerance tests provoked paralytic attacks. Glucose tolerance test also aggravated his cardiac dysrhythmia. Acetazoramide administration improved his paralytic attack. Potassium-sensitive periodic paralysis with cardiac dysrhythmia can not be defined by the classification of periodic paralysis based on the serum potassium concentration. Provocative tests should be done to make a definite diagnosis and treatment should be done taking into consideration both paralytic attack and cardiac dysrhythmia.

Spinal extradural meningeal cyst. Case report.

The case of a 30-year-old man with a spinal extradural meningeal cyst in the thoracolumbar region is reported. Operative findings revealed a dural defect that allowed communication between the extradural cyst cavity and the subarachnoid space. Application of the Valsalva maneuver made the cerebrospinal fluid flow into the cyst cavity; however, reverse flow did not occur. These findings indicate that a valvelike mechanism developed in the enlarging cyst. Surgical resection of the cyst wall and closure of the dural defect provided a favorable result.

[Keratitis and corneal edema associated with levodopa use--a case report].

We report a patient who developed keratitis and corneal edema during treatment with carbidopa-levodopa. The patient was a 34-year-old woman who complained of apraxic gait after anoxic brain damage caused by ventricular arrhythmia. She had difficulty in walking. While doses of droxidopa, flecainide acetate and amantadine HCl were kept at the same levels as before several weeks, administration of carbidopa-levodopa was gradually increased from an initial dose of 100 mg per day to 300 mg per day over a period of 10 days in an attempt to relieve her apraxic gait. Ten days after initiation of treatment with carbidopa-levodopa, her postural instability and unsteady gait slightly improved. However, after 8 days of treatment with carbidopa-levodopa, she complained of blurred vision. Ophthalmologic examination showed keratitis (corneal endothelitis) and corneal edema. After stopping carbidopa-levodopa, the keratitis dramatically improved. Cessation of the drug therapy resulted in a return of vision to normal levels by the 7th day. Although there had been no previous reports of corneal lesion caused by levodopa, we suspected that keratitis and corneal edema were associated with carbidopa-levodopa use, especially in combination treatment with flecainide acetate, and amantadine HCl. The process was reversible and presumably could have been prevented by a shorter term of medication.

[Marked clinical improvement by plasmapheresis in a patient with stiff-man syndrome: a case with a negative anti-GAD antibody].

We described a 56-year-old man with stiff-man syndrome, who was markedly improved after plasmapheresis therapy. He had a 12-year history of progressive painful stiffness of his back and limbs, muscle cramps and difficulty in walking. He had been taking oral diazepam and prednisolone. On examination the abdominal and paraspinal muscles and limbs were continuously contracting, confirmed by surface and needle electromyography. Antibodies against glutamic acid decarboxylase (GAD) and pancreatic islet cells in the serum were negative, but antinuclear antibody and anti-smooth-muscle antibody were present. The patient underwent a course of 4 double filtration plasma exchanges of 3,000 ml each in an 8-day period. Plasmapheresis resulted in marked clinical improvement. The disappearance of muscular cramps and a reduction of stiffness occurred within 24 hours after the first plasmapheresis, and he was able to walk unassisted. The patient's subjective improvement continued over 4 months after the plasma exchange. This case provides additional evidence of the autoimmune mechanism of stiff-man syndrome. Plasmapheresis is one choice in the management for stiff-man syndrome.

[Syndrome of contracture facio-brachio-abdomino-crurale en flexion in a case of isolated ACTH deficiency--biopsy findings of muscle and nerve].

A 55-year-old woman presented with a one-year history of painful muscle cramps and progressive flexion contractures of the arms, pelvic girdles and knees. Laboratory evaluation was summarized as follows: low plasma cortisol and ACTH levels, delayed response of plasma cortisol to ACTH administration, no response of plasma ACTH level to insulin administration, and normal plasma LH, FSH, GH, TSH and PRL levels. She was diagnosed as isolated ACTH deficiency. EMG was silent in contractured muscles at rest. Biopsy of the biceps femoris muscle revealed a marked reduction in fiber size, type 2 fiber atrophy and type 1 fiber predominance. The nerve conduction velocities of the peripheral nerves were found to be decreased. The biopsied specimen of the sural nerve revealed a loss of large myelinated fibers and segmental demyelination. Both flexion contractures and nerve conduction velocities were gradually improved with the replacement of hydrocortisone.