Residual sensorimotor functions in a patient after right-sided hemispherectomy

Sensorimotor functions were examined in a patient with left-sided infantile hemiparesis who underwent hemispherectomy (HS) on the right side at age 18 for intractable epilepsy. Pathological examination of the removed hemisphere showed a porencephalic cyst of the temporal lobe and of the frontoparietal operculum. On examination, the patient had hemianopia to the left and sensorimotor deficits only of the distal limbs contralateral to the HS. She walked with a barely perceptible limp. Axial and proximal movements were quasi normal, so that the patient could fully elevate both arms, flex and extend the forearm with nearly normal power and execute small, isolated precision movements of the arm around the shoulder joint. This astonishing proximal motor repertoire was mimicked on the somatosensory side where cutaneous sensation and kinesthesia were normal above the elbow and knee and contrasted the pronounced distal sensorimotor dysfunctions. Movement analysis by means of an optoelectronic two-camera position analysis system (Selspot II) showed normal flexion-extension synergies during gait, but abnormal synergic coupling between the shoulder and elbow joint during reaching and prehension. Distal movements were still possible but could only be performed as rigidly coupled movement synergies, such as closing and opening of the fist along with arm adduction/flexion or abduction/extension. She could engage these synergies for grasping and holding large objects. The performance of individual, fractionated finger movements was impossible. Involuntary mirror movements were elicited in both the affected and the normal arm, but with distinctly different phase relationships, indicating that different circuitries contribute to their generation. The case study reveals the existence of a bilaterally organized sensorimotor system that has the potential to provide quasi normal performance of the axial-proximal body parts on both sides. This raises the question why this potential cannot be better used in cases with only partial unilateral brain damage and persistent hemiplegia.     

Tachycardia in a patient with mild traumatic brain injury

Clinical Autonomic Research -     

Difficulty in reading braille caused by a right-sided lesion in a blind patient

A right-handed woman who became blind at 25 was a good braille reader. After a right parieto-occipital brain damage, she developed a braille reading disorder which contrasted with a completely normal language. This reading disability cannot be analysed in terms of left hemineglect syndrome; rather, it is explained in the broader context of the patient's haptic disorders in many others fields. This hypothesis is connected to others works which suggest a right hemispheric specialization for tactile information processing.     

Increase in regional cerebral blood flow of striatum induced by low dose levodopa in a patient with hemiparkinsonism]

A 54-year-old woman was admitted to our hospital because of left-sided rigidity. Neurological examination revealed cogwheel-type rigidity in the left upper and lower limbs without tremor. A brain MRI showed no abnormal findings. She was diagnosed as having left-sided hemiparkinsonism. A 99mTc-ECD SPECT detected a decrease in regional cerebral blood flow (rCBF) in the right corpus striatum. Administration of levodopa/DCI (100 mg/day) improved not only her left-sided rigidity but also the rCBF in the right corpus striatum. The ratio of rCBF in the right corpus striatum to that in the left corpus striatum increased from 96.03% to 99.26% on the three-dimensional stereotactic ROI template. These findings suggest that L-dopa may directly activate the metabolism in the bilateral corpus striatum, and that rCBF in the corpus striatum may be increased indirectly according to the increase of movement in the legs. And also it is suggested that denervation supersensitivity to dopamine may exist in the corpus striatum on the contralateral side of the signs and symptoms in this patient with hemiparkinsonism.     

Investigation of neuropsychological characteristics of very mild and mild dementia with Lewy bodies

Introduction: The study aimed to compare the profile of very mild and mild dementia with Lewy bodies (DLB) patients with disease duration up to 5 years in order to find markers for faster progression in this early stage. Method: We investigated 45 DLB patients with disease duration up to 5 years and 22 normal controls. DLB patients were divided into two subgroups on the basis of the Mini-Mental State Examination (MMSE): very mild and mild. Results: Compared to normal controls, very mild DLB patients show significant deficits on tests for attention/executive functions, language, visuospatial/constructional abilities, and retrieval of the episodic memory. In addition, mild DLB (mDLB) patients show a significantly lower score on recall and recognition of the Free and Cued Selective Reminding Test (FCSRT), Trail Making Test Part B (TMT–B), Stroop test, verbal fluency, and Clock Drawing Test than did very mild DLB (vmDLB) patients. Patients with mDLB also have more visual hallucinations, but not significant motor differences compared to vmDLB. Conclusions: In the present work we found that faster progression to the mild DLB stage in the first few years of the disease is mainly related to deterioration of memory, attention/executive functions, and visuospatial abilities, as well as an increased frequency of visual hallucinations.     

Heterogeneity in executive impairment in patients with very mild Alzheimer's disease

BACKGROUND/AIMS: The presence of executive impairment in mild Alzheimer's disease (AD) has primarily been demonstrated by means of group comparison. Whether executive dysfunction is a common feature of mild AD or only present in a subgroup of patients remains unclear. The aim of this study was to describe the frequency of impairment on a set of internationally well-known executive tests in patients with very mild AD. METHODS: Thirty-six patients with very mild AD (MMSE scores above 23) and 32 healthy control subjects were administered a battery of 7 executive tests: Trail Making part B, Stroop Interference Test, modified Wisconsin Card Sorting Test (WCST), category- and letter-based verbal fluency, a design fluency task and the Similarities subtest from WAIS. Impairment was defined as a score of 2 SD or more below control means. RESULTS: Executive impairment on at least 1 measure was seen in 76% of the patients, and 50% were impaired on 2 or more tests. Trail Making B and Stroop Interference Test were impaired in more than 40%, whereas only few patients were impaired on Similarities, WCST and design fluency. A wide variation of executive test profiles was seen among the patients. CONCLUSION: Executive impairments are common in early AD and not just a feature characteristic of a subgroup of patients. Complex attentional skills are more frequently affected than other executive functions. There is, however, considerable heterogeneity among AD patients in the pattern of executive dysfunction.     

Somatosensory potentials in hemiparkinsonism

For a trial of explaining of the occurrence of sensory symptoms in Parkinson's disease evoked somatosensory potentials were studied in 10 patients with hemiparkinsonism and paraesthesiae on the side of the parkinsonian signs. Somatosensory evoked potentials were compared after stimulation of the median nerve on the side of parkinsonian signs with those obtained after stimulation of this nerve on the asymptomatic side. No statistically significant differences were found in the latency of various components of the evoked potentials between both sides of the body. Only slight differences were observed in the morphology of the evoked potentials which were difficult for statistical interpretation.     

Anosognosia in very mild Alzheimer's disease but not in mild cognitive impairment

OBJECTIVE: To study awareness of cognitive dysfunction in patients with very mild Alzheimer's disease (AD) and subjects with mild cognitive impairment (MCI). METHODS: A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were > or =24 in all cases. The discrepancy between the patients' and caregivers' estimations of impairments was taken as a measure of anosognosia. RESULTS: Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001). CONCLUSIONS: While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver's assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE > or =24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver.     

A case of Fukuyama-type congenital muscular dystrophy with a very mild mental deficit

A boy had the clinical features of congenital muscular dystrophy with a very mild mental deficit. A muscle biopsy at one year of age showed the typical findings of Fukuyama-type congenital muscular dystrophy, including selective loss of immunoreactions for alpha dystroglycan. Magnetic resonance imaging showed no findings suggestive of migration disorders. The diagnosis of Fukuyama-type congenital muscular dystrophy was confirmed by a molecular assay at 8 years of age, and his haplotype analysis was heterozygous. At 9 years of age, his FIQ on the Wechsler Scale for Children revealed 69, while his IQ on the Tanaka Binnet scale of intelligence was 97. In this report the relationship between mild clinical condition of the studied case and its genotype is discussed.     

Atypical MRI findings in Canavan disease: a patient with a mild course

Canavan disease is a severe, progressive leukodystrophy with an autosomal recessive inheritance, caused by aspartoacylase (ASPA) deficiency. The characteristic MRI features include diffuse, symmetrical white matter degeneration in the subcortical areas, with bilateral involvement of the globus pallidus. Proton magnetic resonance spectroscopy of the brain shows an increase in the concentration of N-acetylaspartic acid (NAA). The altered NAA metabolism has been traced to mutations in the gene encoding ASPA, located on chromosome 17 (17p13-ter). We present here a patient with a mild form of Canavan disease confirmed with the absent ASPA activity, atypical MRI findings, related to compound heterozygosity for a missense mutation, p.Tyr288Cys, and the known pan-European mutation, the p.Ala305Glu.     

A novel PLP mutation in a Japanese patient with mild Pelizaeus-Merzbacher disease

Pelizaeus-Merzbacher disease (PMD) is a rare dysmyelinating disorder due to mutations in the proteolipid protein (PLP) gene. PLP gene mutations are responsible for a broad spectrum of disease, from the most severe form, connatal PMD, to a less severe form, spastic paraplegia 2 (SPG2). We describe here a very mild case of PMD in a patient who presented with nystagmus in early infancy and was unable to walk until 1 year 7 months of age. Brain magnetic resonance imaging (MRI) at 1 year 7 months of age revealed white matter abnormalities typical of PMD. Genetic testing revealed a novel mutation of the PLP gene (Gly197Arg). The patient presented with only mildly ataxic gait and slurred speech at the age of 4 years. Gly197Arg is the first novel mutation located within exon 4 of the PLP gene and associated with mild PMD/SPG2 in a Japanese patient.     

A new truncating MPZ mutation associated with a very mild CMT1 B phenotype

We have investigated a 34-year-old female who had mild clinical and electrophysiological features of demyelinating peripheral neuropathy. She presented a novel frameshift mutation (V160fsX3) in the exon 4 of the Myelin Protein Zero (MPZ) gene. Clinical and genetic studies performed on her family revealed the same mutation in her oligosymptomatic mother and sister. Our report expands the number of MPZ mutations and indicates that mutations in exon 4 may cause a mild Charcot–Marie–Tooth type 1B phenotype.     

Regional blood flow in hemiparkinsonism

Positron emission tomography was used to measure global and local blood flow in 11 patients with hemiparkinsonism (before and after an acute oral dose of L-dopa) and in 26 normal subjects. Global hemispheric blood flow was not significantly different between the patients [45 +/- 11 ml/(min X 100 g)] and the controls [49 +/- 8 ml/(min X 100 g)]. After L-dopa, the patients' mean global hemispheric flow did not change. Measurements of local blood flow from specific, anatomically defined cortical and basal ganglia regions were performed using a newly developed stereotactic localization technique. Before L-dopa, mesocortical blood flow contralateral to the patients' symptoms was significantly less than controls (p less than 0.003), suggesting a specific abnormality in the cortical dopaminergic projection from the ventral tegmental area. In addition, right and left pallidal blood flow were significantly less tightly coupled in patients than controls (p = 0.0312). After L-dopa, the mesocortical blood flow remained below normal, whereas pallidal blood flow was no longer significantly different from controls (p greater than 0.05).