Biomedical subjects

Lucio Marinelli

Publications and source records attributed to Lucio Marinelli.

6 recordsLinked to original sources

PubMed2006

Bilateral impairment of intracortical inhibition in delayed-onset posthemiplegic dystonia: pathophysiological implications.

OBJECTIVE: To study short interval intracortical inhibition (SICI) in a rare patient with segmental dystonia of the left upper limb due to a vascular lesion in the contralateral putamen without corticospinal tract involvement. METHODS: Paired-pulse transcranial magnetic stimulation (TMS) was applied to both hemispheres in a conditioning-test paradigm. Six interstimulus intervals (ISIs) and 4 conditioning stimulation intensities were investigated in two separate sessions. RESULTS: Motor evoked potentials upon single-pulse TMS were within the normal range, whereas paired-pulse TMS revealed major changes in cortical excitability, proving that SICI was bilaterally absent. CONCLUSIONS: The bilateral impairment of SICI cannot be considered the cause of dystonic contractions, but just a predisposing factor. SIGNIFICANCE: The absence of SICI might be regarded as a condition able to promote maladaptive plastic changes triggered by focal lesions in the putamen.

Adult↗

PubMed2006

A comparative study of primary and secondary hemifacial spasm.

BACKGROUND: Hemifacial spasm (HFS) is a common movement disorder. OBJECTIVE: To evaluate possible differences in the demographic and clinical features between primary and secondary HFS. DESIGN: In-person interview using a standardized questionnaire to collect demographic and clinical data. SETTING: A multicenter study that included patients with HFS attending 3 Italian academic centers. Patients Two hundred fourteen patients with HFS. MAIN OUTCOME MEASURE: A complete neurological examination assessed the current muscle distribution of spasm and the presence of synkinetic movements between upper and lower facial muscles. RESULTS: The study sample comprised 214 patients with HFS, 81 men and 133 women, having a mean +/- SD age of 65.9 +/- 12.3 years; 164 patients were classified as having primary HFS and 50 patients (48 postparalytic and 2 symptomatic cases) were classified as having secondary HFS. Patients with primary and those with secondary HFS had similar mean +/- SD ages at onset (54.9 +/- 13.5 vs 57.0 +/- 12.8 years), male-female ratios (63:101 vs 18:32), right-sided-left-sided HFS (77:86 [1 bilateral] vs 21:28 [1 bilateral]), and frequencies of familial cases (2.9% vs 2.0%), respectively. Most patients (65.0%) with primary HFS had initial symptoms of periocular muscle contractions alone and had subsequent involvement of the lower facial muscles. Most patients (72.0%) with secondary HFS reported initial involvement of the upper and lower facial muscles simultaneously. Signs of synkinesis were present in primary (43.3%) and secondary (58.0%) HFS. CONCLUSIONS: Patients with primary and those with secondary HFS share common demographic and clinical features, including sex distribution, age at onset, affected side of HFS, synkinesis, and rarity of familial cases. Signs of synkinesis were present in significant proportions of patients with primary or secondary HFS. The 2 forms differed in clinical presentation.

Adolescent↗

PubMed2006

Posturographic analysis of balance control in patients with essential tremor.

Essential tremor (ET) is a common movement disorder causing an important functional disability. ET is generally regarded as a monosymptomatic disorder, but additional signs may be present. We analyzed postural sway in 19 patients with classic ET and in 19 sex- and age-matched normal controls (NC) to uncover possible abnormalities of balance control. Static posturography was performed with eyes open (EO) and closed during quiet stance and during performance of mental calculation or motor sequence of thumb opposition to the other fingers. No significant differences of center of foot pressure (COP) parameters were observed between patients and controls during quiet standing. Visual deprivation induced a similar worsening of postural sway in both groups. Concomitant performance of a cognitive or motor task did not affect COP area, whereas COP path was significantly modified by the cognitive task in both groups. In all EO conditions, the COP path was significantly lower in NC than in ET, but such offset was related only to the group of ET patients with head tremor. This study demonstrates that balance control is only minimally affected in ET, although patients with head involvement and longer disease duration tend to present a reduced postural stability. The "dual-task effect" is less important in ET than in Parkinson's disease patients.

Adult↗

PubMed2005

Relationship between eye symptoms and blepharospasm: a multicenter case-control study.

Although patients with primary blepharospasm (BSP) commonly report experiencing ocular symptoms before the onset of orbicular spasms, the precise frequency and pathogenic role of this subjective ocular discomfort are poorly understood. We conducted a multicenter case-control study to investigate symptoms related to disorders of the anterior segment of the eye, administering a questionnaire to 165 patients with BSP and 180 age- and gender-matched control patients with hemifacial spasm. On a validation sample, our questionnaire yielded high accuracy in detecting eye diseases (predominantly, dry eye syndrome) using detailed ophthalmological examination as the criterion. Logistic regression analysis indicated a significant association between ocular symptoms at disease onset and BSP. Ocular symptoms starting in the year preceding disease onset (short-latency symptoms) showed a stronger association with BSP than ocular symptoms occurring earlier in time (long-latency symptoms). The association was stronger when short-latency symptoms developed from 40 to 59 years of age, whereas this was not observed for long-latency symptoms. Our findings support the view that eye symptoms associated with BSP result from eye diseases and may be involved in the pathogenesis of BSP. The differential risk of developing BSP, based on age at onset of ocular symptoms, suggests that age and eye diseases may interact in giving rise to BSP.

Age of Onset↗

PubMed2004

Suppression of the transcallosal motor output: a transcranial magnetic stimulation study in healthy subjects.

We tested the hypothesis that transcranial magnetic stimulation (TMS), in addition to its inhibitory action on the corticospinal output, can also exert some inhibitory effect on the transcallosal system connecting the two motor cortices. In seven normal subjects, instructed to keep their right opponens pollicis (OP) muscle fully relaxed and their left OP muscle voluntarily contracted, we used a paired-pulse TMS protocol, to stimulate the left motor cortex. We evaluated the effect of low-intensity conditioning stimulation on the ipsilateral silent period (iSP) elicited by the subsequent test stimulus. Compelling evidence exists to support that this iSP is mediated by the activation of transcallosal motor fibres. Simultaneously, the inhibition of the motor evoked potential (MEP) in the right OP muscle was also investigated. At the interstimulus interval (ISI) of 3 ms, the iSP was significantly (P<0.0001, repeated-measures ANOVA) suppressed by conditioning intensities ranging from 1.2 to 0.6 of MEP threshold. The assessment of the time-course showed that iSP inhibition was present in all the tested subjects only at ISIs of 2 and 3 ms (for each subject P<0.05, repeated-measures ANOVA). Several findings suggest that the suppression of iSP is brought about by the activation of inhibitory mechanisms operating in the stimulated (left) motor cortex. We propose that the assessment of iSP suppression could be a method to study the excitability of intracortical inhibitory circuits in the affected hemisphere of patients with unilateral damage of the corticospinal tract.

Adult↗

PubMed2004

Muscle relaxation is impaired in dystonia: a reaction time study.

A simple visual reaction time (RT) paradigm was used to investigate whether the velocity of relaxation is impaired in dystonia. In 16 subjects with a clinical diagnosis of adult-onset focal, segmental or multifocal dystonia and in 15 age-matched normal controls, the relaxation reaction time (R-RT) and the contraction reaction time (C-RT) were compared across different tasks involving the flexor carpi radialis (FCR), biceps brachii (BB) and triceps brachii (TR) arm muscles. In normal controls, the latency of EMG termination (R-RT) was significantly shorter than the latency of electromyographic (EMG) onset (C-RT) in the BB and TR muscles, but not in the FCR muscle. In dystonic patients, the latency of EMG termination (R-RT) was significantly longer than the latency of EMG onset (C-RT) in the FCR and BB muscles. No significant difference of the C-RT was observed between patients and controls whereas the R-RT was prolonged significantly in the BB and TR muscles of patients with dystonia and almost significantly in the FCR muscle. This study indicates that muscle relaxation is abnormal in patients with focal (multifocal or segmental) dystonia. The impaired muscle relaxation may contribute to the longer overlap of agonist-antagonist activities (co-contraction) typically observed in dystonia and to the slowness of voluntary movement sequencing.

Adult↗