Dopamine denervation in the functional territories of the striatum: a new MR and atlas-based 123I-FP-CIT SPECT quantification method.

Current quantification methods of 123I-FP-CIT SPECT rely on anatomical parcellation of the striatum. We propose here to implement a new method based on MRI segmentation and functional atlas of the basal ganglia (MR-ATLAS) that could provide a reliable quantification within the sensorimotor, associative, and limbic territories of the striatum. Patients with Parkinson's disease (PD), idiopathic rapid eye movement sleep behavioral disorder (iRBD), and healthy controls underwent 123I-FP-CIT SPECT, MRI, motor, and cognitive assessments. SPECT data were corrected for partial volume effects and registered to a functional atlas of the striatum to allow quantification in every functional region of the striatum (nucleus accumbens, limbic, associative, and sensorimotor parts of the striatum). The MR-ATLAS quantification method is proved to be reliable in every territory of the striatum. In addition, good correlations were found between cognitive dysexecutive tests and the binding within the functional (limbic) territories of the striatum using the MR-ATLAS method, slightly better than correlations found using the anatomical quantification method. This new MR-ATLAS method provides a robust and useful tool for studying the dopaminergic system in PD, particularly with respect to cognitive functions. It may also be relevant to further unravel the relationship between dopaminergic denervation and cognitive or behavioral symptoms.

Comparing ataxias with oculomotor apraxia: a multimodal study of AOA1, AOA2 and AT focusing on video-oculography and alpha-fetoprotein.

Whether the recessive ataxias, Ataxia with oculomotor apraxia type 1 (AOA1) and 2 (AOA2) and Ataxia telangiectasia (AT), can be distinguished by video-oculography and alpha-fetoprotein level remains unknown. We compared 40 patients with AOA1, AOA2 and AT, consecutively referred between 2008 and 2015 with 17 healthy subjects. Video-oculography revealed constant impairments in patients such as cerebellar signs, altered fixation, impaired pursuit, hypometric saccades and abnormal antisaccades. Horizontal saccade latencies could be highly increased reflecting oculomotor apraxia in one third of patients. Specific distinctive alpha-fetoprotein thresholds were determined for AOA1 (7-15 µg/L), AOA2 (15-65 µg/L) and AT (>65 µg/L). Early age onset, severe walking disability, movement disorders, sensori-motor neuropathy and cerebellar atrophy were all shared. In conclusion, alpha-fetoprotein level seems to permit a distinction while video-oculography does not and therefore is not mandatory, even if an appropriate oculomotor examination remains crucial. Our findings are that AOA1, AOA2 and AT form a particular group characterized by ataxia with complex oculomotor disturbances and elevated AFP for which the final diagnosis is relying on genetic analysis. These findings could guide genetic analysis, assist reverse-phenotyping and provide background for the interpretation of the numerous variants of unknown significance provided by next-generation sequencing.

Parkinson's disease associated with 22q11.2 deletion: Clinical characteristics and response to treatment.

BACKGROUND: While it is known that 22q11.2 microdeletions (22q11.2-del) increase the risk of Parkinson's disease (PD), the characteristics of PD associated with 22q11.2-del have not been specifically explored. OBJECTIVE: This report aimed to assess the clinical characteristics and treatment responses of PD patients with 22q11.2-del, and to describe any features that might lead neurologists to investigate the comorbidity. METHODS: Nine PD patients (eight men, one woman) with 22q11.2-del were followed at seven centers of the French PD Expert Network (Ns-Park). RESULTS: PD diagnosis was made before 22q11.2-del diagnosis in seven cases; their main characteristics were early onset (32-48 years) and good initial levodopa sensitivity, but with a course characterized by severe and early-onset levodopa-induced motor complications and psychiatric manifestations. Three patients received deep brain stimulation (DBS) that was effective. CONCLUSION: Searching for 22q11.2-del in PD patients presenting with suggestive features is relevant as the clinical presentation is similar to idiopathic PD, but with other associated characteristics, including a severe evolution. Results with DBS are similar to those reported for idiopathic PD.

"De-novo" consultation: Evaluation of an outpatient's clinic dedicated to early diagnosis of parkinsonian syndromes.

INTRODUCTION: In the absence of specific clinical signs, imaging or biomarkers, the differential diagnosis of degenerative parkinsonian syndromes may be difficult at early stages of the disease. To reduce the risk of misdiagnosis or delayed diagnosis and referral to multiple medical centers at disease onset, easier access to expert centers should be available. To improve the initial care of parkinsonian patients, the Parkinson's disease Expert Center (PEC) at Pitié-Salpêtrière Academic Hospital has set up a specific outpatients clinic with short waiting times dedicated to the diagnosis of early Parkinson's disease and related disorders. METHODS: The PEC setup first identifies requests for diagnostic confirmation of parkinsonian syndromes, then specific outpatients clinic visits are scheduled weekly, with examinations carried out by neurologists at the PEC on a rotating schedule. Data from the first year of the new procedure were analyzed retrospectively through self-administered questionnaires sent to patients seen during this period. The main outcomes were to confirm the ability to keep to short delays for patients' examinations and to assess patients' satisfaction with the setup. RESULTS: Both study outcomes were achieved. The creation of an outpatients clinic dedicated to the early diagnosis of parkinsonian syndromes allowed shorter delays before the first examination of 5 weeks instead of several months. Keeping to the weekly schedule and limited time taken for each visit was also achieved. Following this initial outpatients visit, diagnosis of a parkinsonian syndrome was clinically confirmed or further specified in 80% of cases. A survey of patients' satisfaction showed a rate of over 91% in terms of the timing and course of clinical examinations at our PEC. DISCUSSION/CONCLUSION: This study of our quality-improvement program for Parkinson's disease management has shown that specific consultations with shorter waiting times aiming to allow early specialized assessment of parkinsonian syndromes is beneficial for patients and reduces the risk of delayed diagnoses.

Increased cortico-striatal connectivity during motor practice contributes to the consolidation of motor memory in writer's cramp patients.

Sensorimotor representations of movements are created in the sensorimotor network through repeated practice to support successful and effortless performance. Writer's cramp (WC) is a disorder acquired through extensive practice of finger movements, and it is likely associated with the abnormal acquisition of sensorimotor representations. We investigated (i) the activation and connectivity changes in the brain network supporting the acquisition of sensorimotor representations of finger sequences in patients with WC and (ii) the link between these changes and consolidation of motor performance 24 h after the initial practice. Twenty-two patients with WC and 22 age-matched healthy volunteers practiced a complex sequence with the right (pathological) hand during functional MRI recording. Speed and accuracy were measured immediately before and after practice (day 1) and 24 h after practice (day 2). The two groups reached equivalent motor performance on day 1 and day 2. During motor practice, patients with WC had (i) reduced hippocampal activation and hippocampal-striatal functional connectivity; and (ii) overactivation of premotor-striatal areas, whose connectivity correlated with motor performance after consolidation. These results suggest that patients with WC use alternative networks to reach equiperformance in the acquisition of new motor memories.

[Dural-cavernous fistulas revealed by bilateral alternating third and sixth nerve palsies]. / Fistule durale carotido-caverneuse révélée par une paralysie bilatérale à bascule des troisièmes et sixièmes nerfs crâniens.

A 74-year-old male was referred for disequilibrium, associated with right third and sixth nerve palsies observed 2weeks after head trauma with no loss of consciousness. On clinical examination, 4months after the injury, contralateral (left) third and sixth nerve palsies were observed, while ocular motility was now normal on the right side. The remainder of the ophthalmological examination was normal. Upon further history, tinnitus was found to have been present since the trauma, and auscultation of the preauricular area demonstrated a systolic bruit. Cerebral angiogram confirmed the presence of bilateral dural-cavernous fistulas. Clinical features of indirect or dural-cavernous fistulas and therapeutic options proposed in the literature are reviewed.

TENS is harmful in primary writing tremor.

OBJECTIVE: It is unclear whether primary writing tremor (PWT) is a tremulous form of dystonia or a tremor per se. Transcutaneous electrical nerve stimulation (TENS) at 50 Hz applied for 2 weeks was reported to improve the writing capabilities of patients with writer's cramp (WC). We explored whether such a beneficial effect can be obtained in patients with a PWT. METHODS: In a cross-over, double-blinded randomized study we tested whether 2-week periods of 5, 25 or 50 Hz TENS applied to wrist flexor muscles, improved the score of the Fahn-Tolosa-Marin scale of nine patients with PWT. Excitability of neurons and of various intracortical circuits in the motor cortex were also tested before and after TENS by using transcranial magnetic stimulation. RESULTS: TENS at 5 and 25 Hz did not have any effect while TENS at 50 Hz worsened the clinical condition and the cortical excitability. CONCLUSIONS: TENS is not a new treatment alternative for PWT. SIGNIFICANCE: The beneficial effect in WC and the harmful one in PWT of TENS stresses that the two disorders are likely different nosological entities.

[Movement disorders and neurometabolic diseases]. / Mouvements anormaux et maladies neurométaboliques.

Movement disorders, especially dystonia, are a frequent manifestation of neurometabolic diseases. Proper characterization and classification of movement disorders is crucial but may be challenging in this setting. The diagnostic work-up should be focused first on treatable disease. Mixed movement disorders, marked orofacial involvement and associated neurological and extra-neurological features should prompt the clinician to consider the possibility of an underlying neurometabolic disorder. The diagnostic approach is based on the abrupt, paroxysmal or insidious nature of onset of the movement disorders, the clinical picture including neurological and systemic signs and symptoms, and the presence or absence of abnormalities on the brain MRI. In addition to specific treatment for the metabolic disease, when available, symptomatic treatment of the movement disorders can be proposed, remembering that these patients are particularly vulnerability to iatrogenesis.

The adolescent and adult form of cobalamin C disease: clinical and molecular spectrum.

BACKGROUND: Cobalamin C disease is the most common inborn error of cobalamin metabolism with an autosomal recessive mode of inheritance and mutations within the MMACHC gene. Clinical features, including systemic, haematological and neurological abnormalities, usually occur in the first year of life. Adolescent and adult onset presentations are rare. METHODS: We report on the clinical, molecular and imaging features in three patients aged 40, 42 and 42 years at the last follow-up. We examine these cases together with eight previously described cases to determine the clinical and molecular features of the disease in adults. RESULTS: Mean age at onset of clinical symptoms was 26 years; clinical features included predominant neurological disturbances and thromboembolic complications. White matter abnormalities on brain MRI were sometimes observed. Most patients (eight of nine patients investigated) were compound heterozygotes for the 271dupA mutation and a missense mutation. Intramuscular or intravenous hydroxycobalamin therapy stopped the progression of the disease and resulted in a better clinical outcome and favourable biological status in 7/9 treated cases, while the two untreated patients died quickly. CONCLUSIONS: As cobalamin C disease and related disorders of homocysteine metabolism are treatable conditions, homocysteinaemia should be included in the investigations of patients with progressive neurological deterioration, unexplained psychiatric disturbances or recurrent thromboembolic events.

MR spectroscopic pulvinar sign in a case of variant Creutzfeldt-Jakob disease.

We report MR spectroscopic findings in a patient hospitalized with biopsy-proven variant Creutzfeldt-Jakob (vCJD) disease. N-acetyl aspartate was markedly decreased in the postero-medial part of the thalami (pulvinar) but was not diminished in the parieto-occipital white matter and cortical grey matter. These observations, which are in accordance with the pathological findings in this disease, suggest that MR spectroscopy, a highly sensitive method for the detection of subtle brain metabolic dysfunction, could be of interest for the diagnosis, prognosis and therapeutic follow-up of vCJD.