Movement-related electroencephalographic desynchronization in patients with hand cramps: evidence for motor cortical involvement in focal dystonia

We studied the dynamic changes in the amplitude of scalp electroencephalographic (EEG) oscillations to self-paced simple index finger abduction movements in patients with writer's cramp and compared them with those of normal aged-matched controls. The changes in EEG oscillations were measured in predefined frequency bands (8-10, 10-12, 12-20, and 20-30 Hz) by using the event-related desynchronization technique. Movements of the affected and unaffected hand in patients with writer's cramp showed significantly less reduction in 20- to 30-Hz power compared with controls. The differences in movement-related EEG power decline were apparent over the contralateral central and midline regions before and after electromyographic onset. Because EEG beta rhythm in the sensorimotor region likely emanates from the motor cortex and is related to ongoing muscle activity, this abnormality could be a manifestation of the abnormal motor command at the cortical level.     

Speech-induced primary lingual dystonia: a rare focal dystonia

Lingual dystonia, a type of focal dystonia that may be primary or secondary, is related to brain damage, neuroleptic use, neurodegenerative, metabolic, and neurodevelopmental disorders, varicella infection, and so on. However, primary lingual dystonia induced by speaking is a rare type of focal dystonia that is usually idiopathic in origin and is characterized by increased tonus of the tongue, which causes protrusion only during speaking. This report describes a 55-year-old male patient with lingual dystonia during speech. One interesting clinical feature of this case was that the speech disturbance improved while the patient vocalized a praise-like hymn in a manner that resembled singing.     

Cervical dystonia: clinical and therapeutic features in 85 patients

We studied patients with cervical dystonia (CD) to determine clinical features and response to botulinum toxin A (BoNT/A). Patients were submitted to clinical, laboratory and neuroimaging evaluation. BoNT/A was injected locally in 81 patients using electromyographic guidance. Four patients who had had previous treatment were considered to be in remission. The average ages at onset of focal dystonia and segmental dystonia were greater than for generalized dystonia (p<0.0003). The severity of the abnormal head-neck movements were more severe among the patients with generalized dystonia (p<0.001). Pain in the cervical area was noted in 59 patients. It was not possible to determine the etiology of the disease in 62.3% of patients. Tardive dystonia was the most common secondary etiology. A major improvement in the motor symptoms of CD and pain was observed in patients following treatment with BoNT/A. The tardive dystonia subgroup did not respond to the treatment. Dysphagia was observed in 2.35% of the patients.     

Torsion dystonia,conversion hysteria,and occupational cramps

The field of torsion dystonia is rich in implications for psychiatry. At long last one has the means for approaching cases, often hitherto considered intractable examples of conversion hysteria and psychophysiologic disorders, with rational principles of etiology and treatment. Many unusual and mystifying disorders can now be studied with fresh understanding. It is especially the action dystonias and the occupational cramps that have light shed on them which has long been lacking. Much in the pathophysiology of the dystonias remains to be investigated.     

Genetic and clinical features of primary torsion dystonia

Primary torsion dystonia (PTD) is defined as a syndrome in which dystonia is the only clinical sign (except for tremor), and there is no evidence of neuronal degeneration or an acquired cause by history or routine laboratory assessment. Seven different loci have been recognized for PTD but only two of the genes have been identified. In this review we will describe the phenotypes associated with these loci and discuss the responsible gene. This article is part of a Special Issue entitled "Advances in dystonia".     

Facial dystonia: clinical features, prognosis and pharmacology in 31 patients

The natural history and response to different treatments were assessed in 31 consecutive patients with blepharospasm (BS) and/or oromandibular dystonia (OMD). The mean age at onset was 52.4 years and there was a female preponderance of 2.5 to 1. Ocular symptoms preceded the onset of blepharospasm in more than 50% of the affected patients, whereas psychiatric and dental problems prior to the onset of focal dystonia were found in 10% and 13% of the cases respectively. Dystonia elsewhere, mainly in the craniocervical area, was found in 23% of patients and appeared to follow a somatotopic progression. The first 2–3 years of history were crucial for the spread of dystonia to other face and body parts. When OMD was the first symptom, a lower tendency of dystonia to progress elsewhere was observed. A putative cause was found in 14% of patients who showed clinical and radiographic evidence of basal ganglia or rostral brainstemdiencephalon lesions. The response to different drugs was inconsistent although transient improvement was induced by haloperidol in 6 patients, by L-Dopa plus deprenyl in 3 patients, by trihexyphenidyl in 2 patients and by clonazepam in 2 patients. One, apparently spontaneous, remission was observed. Botulinum A toxin was iniected in the orbicularis oculi of 8 patients affected by BS: moderate to marked improvement lasting 5 to 30 weeks (mean 14.5 weeks) was achieved in all cases; transient ptosis, lasting 1 to 3 weeks, occurred in 3 cases.

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Sommario La storia naturale e la prognosi della distonia faciale sono state valutate in una serie di 31 consecutivi pazienti con blefarospasmo (BS) e/o distonia oromandibolare (OMD) (età di esordio: 19–75 anni; durata di malattia: 1–15 anni; rapporto maschi/femmine: 2.5/1). Sintomi oculari precedevano l'insorgenza del BS in oltre il 50% dei pazienti, mentre anomalie dentali e problematiche psichiatriche comparivano come prodromi nel 10% e nel 13% dei casi rispettivamente. La sintomatologia distonica diffondeva, con andamento somatotopico, oltre il distretto cranio faciale nel 23% dei casi. Evidenze cliniche o radiologiche di lesioni dei gangli della base, della parte rostrale del tronco dell'encefalo o del diencefalo erano presenti solo nel 13% dei casi. Un lieve ma transitorio miglioramento della sintomatologia distonica era indotto da aloperidolo in 6 pazienti, da 1-dopa+deprenyl in 3, da triesifenidile in 2 e da lonazepam in 2. Solo 1 paziente andava incontro a remissione apparentemente spontanea della sintomatologia distonica dopo un anno di malattia. L'iniezione di tossina botulinica di tipo A negli orbicolari delle palpebre di 8 pazienti con BS induceva un sensibile miglioramento della sintomatologia distonica che persisteva per 5–30 settimane (media 14.5 settimane) con ridotti effetti collaterali locali (transitoria ptosi in 3 casi).

     

Facial dystonia: clinical features, prognosis and pharmacology in 31 patients

The natural history and response to different treatments were assessed in 31 consecutive patients with blepharospasm (BS) and/or oromandibular dystonia (OMD). The mean age at onset was 52.4 years and there was a female preponderance of 2.5 to 1. Ocular symptoms preceded the onset of blepharospasm in more than 50% of the affected patients, whereas psychiatric and dental problems prior to the onset of focal dystonia were found in 10% and 13% of the cases respectively. Dystonia elsewhere, mainly in the craniocervical area, was found in 23% of patients and appeared to follow a somatotopic progression. The first 2–3 years of history were crucial for the spread of dystonia to other face and body parts. When OMD was the first symptom, a lower tendency of dystonia to progress elsewhere was observed. A putative cause was found in 14% of patients who showed clinical and radiographic evidence of basal ganglia or rostral brainstemdiencephalon lesions. The response to different drugs was inconsistent although transient improvement was induced by haloperidol in 6 patients, by L-Dopa plus deprenyl in 3 patients, by trihexyphenidyl in 2 patients and by clonazepam in 2 patients. One, apparently spontaneous, remission was observed. Botulinum A toxin was iniected in the orbicularis oculi of 8 patients affected by BS: moderate to marked improvement lasting 5 to 30 weeks (mean 14.5 weeks) was achieved in all cases; transient ptosis, lasting 1 to 3 weeks, occurred in 3 cases.

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Sommario La storia naturale e la prognosi della distonia faciale sono state valutate in una serie di 31 consecutivi pazienti con blefarospasmo (BS) e/o distonia oromandibolare (OMD) (età di esordio: 19–75 anni; durata di malattia: 1–15 anni; rapporto maschi/femmine: 2.5/1). Sintomi oculari precedevano l'insorgenza del BS in oltre il 50% dei pazienti, mentre anomalie dentali e problematiche psichiatriche comparivano come prodromi nel 10% e nel 13% dei casi rispettivamente. La sintomatologia distonica diffondeva, con andamento somatotopico, oltre il distretto cranio faciale nel 23% dei casi. Evidenze cliniche o radiologiche di lesioni dei gangli della base, della parte rostrale del tronco dell'encefalo o del diencefalo erano presenti solo nel 13% dei casi. Un lieve ma transitorio miglioramento della sintomatologia distonica era indotto da aloperidolo in 6 pazienti, da 1-dopa+deprenyl in 3, da triesifenidile in 2 e da clonazepam in 2. Solo 1 paziente andava incontro a remissione apparentemente spontanea della sintomatologia distonica dopo un anno di malattia. L'iniezione di tossina botulinica di tipo A negli orbicolari delle palpebre di 8 pazienti con BS induceva un sensibile miglioramento della sintomatologia distonica che persisteva per 5–30 settimane (media 14.5 settimane) con ridotti effetti collaterali locali (transitoria ptosi in 3 casi).

     

Isolated lingual dystonia induced by speaking: a rare form of focal dystonia

Focal lingual dystonia is a rare condition that can be misdiagnosed as a psychogenic problem because it may interfere with chewing, swallowing, and speaking. We present a patient with an uncommon type of dystonia (speech-induced primary lingual dystonia), that responded well to botulinum toxin injection.     

Hereditary recurrent focal neuropathies: clinical and molecular features

The authors review the molecular genetics and pathophysiology of hereditary recurrent focal neuropathies: hereditary neuropathy with liability to pressure palsies (HNPP) and hereditary neuralgic amyotrophy (HNA). Significant progress in the understanding of HNPP and HNA has been achieved. HNPP and HNA are distinct clinical and pathologic disease entities with autosomal dominant inheritance. Molecular genetic studies have shown that HNPP and HNA are located on chromosome 17 but at distinct genetic loci (17p11.2 for HNPP, 17q25 for HNA). The 1.5 megabase deletion in 17p11.2 is the major cause of HNPP. This interstitial deletion causes the complete loss of one allele of the peripheral myelin protein 22 (PMP22) gene. Interestingly, rare HNPP patients are found without the 1.5 megabase deletion. However, these patients have distinct mutations in the PMP22 gene resulting in altered expression of the PMP22 protein. Current molecular genetic tests and clinical guidelines allow improved diagnosis, prognosis, and genetic counseling for patients with HNPP. Such tests are not available for HNA, because the disease-causing gene remains unknown. Molecular genetic advances in HNPP and HNA, as well as the study of transgenic animal and cellular models, will provide a more precise understanding of the disease mechanisms and will lead to the development of effective therapeutic tools for patients with inherited and sporadic recurrent peripheral neuropathies.     

Unilateral pure thalamic asterixis: clinical, electromyographic, and topographic patterns

Eleven patients (nine with infarctions and two with primary hematomas) with isolated thalamic lesions and contralateral asterixis were examined using a standard electromyographic and neuroimaging protocol. Asterixis was a short-duration phenomenon associated with a hemiataxia hypesthesia syndrome in all patients. Electromechanical synchronization was constant for the two silent period types. The anatomic data strongly suggest that ventral lateral or lateral posterior thalamus are concerned in the pathophysiology of thalamic asterixis.     

Mild parkinsonian features in dystonia: Literature review,mechanisms and clinical perspectives

Dystonia is a hyperkinetic movement disorder that can be highly stigmatizing and disabling. Substantial evidence from animal models, neuropathological, neurophysiological, neuroimaging and clinical studies emphasizes the role of dopaminergic dysfunction in the pathophysiology of dystonia, illustrating possible pathophysiological overlap with parkinsonism. Furthermore, basal ganglia dysfunction has been implicated in the pathogenesis of dystonia, and is well established to underlie the manifestations of Parkinson's disease. Clinically, parkinsonian features are a key characteristic of some combined dystonias, including dopa-responsive dystonia, and Parkinson's disease often presents with dystonia. Moreover, many treatments effective in Parkinson's disease, both medical and surgical, also offer some benefit in dystonia. Therefore, mild parkinsonian features might logically accompany idiopathic and inherited isolated dystonias. However, as the current literature is particularly scant, the present review aimed to investigate mild parkinsonism in idiopathic and inherited dystonia. We found limited evidence alluding to the presence of mildly reduced arm-swing, increased tone, and non-decremental bradykinesia in adult-onset focal dystonia. Tremor, with postures, action and rest, also occurs commonly in idiopathic isolated dystonia, and can simulate Parkinson's disease tremor and be a cause of ‘scans without evidence of dopaminergic deficit’. Parkinsonian features in monogenic isolated dystonias have been less well investigated, despite the potential benefit of correlating pathophysiological and clinical findings. The recognition and improved clinical characterization of parkinsonian features in idiopathic and inherited isolated dystonia extends the clinical spectrum of motor features in dystonia, which may help avoid incorrect diagnosis and inform therapeutic research.     

Clinical features of dystonia: a pathophysiological revisitation

PURPOSE OF REVIEW: To elucidate the pathophysiology of some clinical features of dystonic patients and to provide some new insight into the mechanisms underlying task-specific dystonia. RECENT FINDINGS: There are three general lines of work at the present time that may indicate the physiological substrate for dystonia. All three are persuasive and it is not clear whether they are related to each other or whether one is more important than the others. According to the first line of research, a loss of inhibition at different levels of the central nervous system might contribute for the excessive movement seen in dystonia. Another field of research suggests that dystonic patients may have faulty processing within the lemniscal pathway with abnormalities in the sensory-motor integration. Finally, another convincing line of evidence is that in some susceptible individuals, during the acquisition of new motor skills, the mechanisms of neuroplasticity are subtly abnormal. In the presence of such predisposition, several environmental factors, such as repetitive training or peripheral nervous system injury, can trigger an abnormal maladaptive plasticity, which can lead to an overt dystonia. SUMMARY: These findings may be relevant in the development of new therapeutic strategies in dystonia.     

Botulinum toxin in cervical dystonia: low dosage with electromyographic guidance

Sixty patients with idiopathic cervical dystonia were treated a total of 240 times with botulinum toxin type A (BTA). Selected muscles were injected with BTA under electromyographic (EMG) guidance. The clinical effect was measured on the Tsui scale and a 10-point anchored visual analogue scale. A dosage of 150–300 mouse units was used in 77% of the treatments (mean 204 mouse units). Based on the Tsui scale, 45% of 240 treatments were still effective at the moment of reinjection (median improvement 2 points). Based on the 10-point anchored visual analogue scale, 73% of treatments were successful (median improvement 3 points). Forty-eight patients (80%) responded favourably to the treatment. Side-effects were mild and transient. Dysphagia occurred in 9% of treatments. Antibody production was investigated in 41 patients and was negative in all. A striking difference from previous reports is the lower dosage used in this study. The clinical response, however, was similar to that of other studies. We conclude that a dosage of 200–400 mouse units BTA (Dysport) may also be effective in the treatment of cervical dystonia, but with fewer side effects. EMG guidance and application of BTA into deep cervical muscles may further improve the clinical effect.     

Chondrodystrophic myotonia: electromyographic and cardiac features of a case

The Schwartz-Jampel syndrome or chondrodystrophic myotonia is a rare disease characterized by dwarfism, diffuse osteoarticular alterations, ble-pharospasm, perioral muscular contractions and electromyographic alterations. The authors present a case of chondrodystrophic myotonia focusing mainly on facial electromyographic and cardiac findings. The electromyo-graphy of the orbicularis oculi muscles showed abundant myotonic discharges like other facial muscles as well as muscles of the members. It was not possible to obtain true electrical silence between myotonic discharges, suggesting that the blepharospasm is a consequence of persistent muscular contraction. No conclusive evidence of myocardiopathy was given by clinical or laboratory cardiac examinations. General characteristics of the syndrome are discussed as well as the treatment with procamide and phenytoin.     

Psychiatric disorders in idiopathic-isolated focal dystonia

Idiopathic-isolated focal dystonia (IIFD) is a movement disorder characterised by involuntary, sustained muscle contractions, leading to abnormal postures. Psychopathology is frequent in patients with IIFD, and while traditionally this was thought to be a secondary phenomenon, there is emerging evidence for shared neurobiological mechanisms. We conducted a single-centre cross-sectional study of 103 consecutive patients with IIFD and two comparison groups: 78 consecutive patients with hemifacial spasm (HFS) and 93 healthy control subjects. Assessments with regard to psychiatric disturbances were performed using self-report questionnaires, including the self-report version of the Yale–Brown Obsessive Compulsive Scale (Y-BOCS-SR), the Beck Anxiety Inventory (BAI), and the Beck Depression Inventory (BDI). Compared to healthy control subjects and patients with HFS, the IIFD group had higher OCS, anxiety, and depression scores as measured by the Y-BOCS-SR, BAI, and BDI, respectively. The Y-BOCS-SR, BAI, and BDI were highly correlated across all the subjects. Logistic regression analysis showed that the main driver of high obsessive–compulsive symptom scores, irrespective of neurological diagnosis, was the BDI, whereas it was BAI (and not BDI), that drives the association between the psychiatric rating scale scores and the neurological diagnosis. Our findings suggest that while clinically significant obsessive–compulsive symptoms are over-represented in IIFD patients relative to controls, the BAI may have better discriminatory power to distinguish between the psychiatric symptoms in IIFD patients.