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Clinical Neuroscience

JULY 30, 2020

[Recurrent inhibition during Jendrassik maneuver]

LUKÁCS Miklós

[Objective – Conflicting theoretical models exist regarding the mechanism related to the ability of the Jendrassik maneuver to reinforce reflex parameters. Our objective was to investigate if vigorous handgrip would induce changes in recurrent inhibition of soleus motoneurons. Method – Soleus H reflex was evoked by stimulating the tibial nerve at rest and during bilateral vigorous handgrip, alternating single (H1) and paired stimulation (H2). At paired stimulation we used interstimulus intervals of 10, 15, 20 and 25 ms and supramaximal test stimulus. H1- and H2-wave amplitudes were expressed as percentage of maximal M-wave amplitude. Conditioned H2 wave maximal (H2max) and minimal (H2) amplitudes evoked at rest and expressed as a percentage of the unconditioned H1max amplitude were compared with the corresponding values obtained during handgrip by means of paired Student test and Bonferroni correction. Subjects – At the study participated 28 healthy volunteers. Results – The H1max/Mmax × 100 values obtained during handgrip (37.5±10.1) were significantly higher than those obtained at rest (27.1±7.4). The H2max/H1max × 100-va­lues obtained at paired stimulation were significantly higher during handgrip than at rest, while no significant diffe­rence was found between the H2/H1max × 100-values obtained during handgrip and at rest respectively. Discussion – The H2max/H1max is determined by both the excitability of the motoneurons and the recurrent inhibition elicited by the conditioning stimulus, while H2/H1max indicates only the level of recurrent inhibition. According to our results the Renshaw cells retain their inhibitory effect on the soleus alpha motoneurons during remote muscle contraction. Conclusion – Soleus H reflex enhancement during Jendrassik maneuver is not due to decrease of recurrent inhibition. ]

Clinical Neuroscience

MAY 30, 2020

[The long-term follow-up of enzyme replacement treatment in late onset Pompe disease]

MOLNÁR Mária Judit, BORSOS Beáta, VÁRDI Visy Katalin, GROSZ Zoltán, SEBÕK Ágnes, DÉZSI Lívia, ALMÁSSY Zsuzsanna, KERÉNYI Levente, JOBBÁGY Zita, JÁVOR László, BIDLÓ Judit

[Pompe disease (PD) is a rare lysosomal disease caused by the deficient activity of acid alpha-glucosidase (GAA) enzyme due to mutations in the GAA gene. The enzymatic deficiency leads to the accumulation of glycogen within the lysosomes. Clinically, the disease has been classically classified in infantile and childhood/adult forms. Presently cc. close to 600 mutations distributed throughout the whole gene have been reported. The c.-32-13T>G splice mutation that is very common in patients of Caucasian origin affected by the childhood/adult form of the disease, with an allelic frequency close to 70%. Enzyme replacement treatment (ERT) is available for the patients with Pompe disease (Myozyme). In this paper, we are presenting the long term follow up of 13 adult onset cases treated more than 5 years. The longest follow up was 15 years. To evaluate the treatment efficacy, the 6 minutes walking test (6MWT) and the respiratory functions were monitored annually. The analysis revealed that at the beginning of ERT for 3-4 years the 6MWT had been generally increasing, then it declined, and after 10 years it was lower in 77% of the cases than it had been at the start of the treatment. In 23% of the cases the 6MWT increased during the follow up time. Only one of the patients become wheelchair dependent during the follow-up period. The respiratory function showed similar results especially in supine position. A high degree of variability was observed among patients in their responses to the treatment, which only partially associated with the antibody titer against the therapeutic protein. The efficacy of the ERT was associated with the type of the disease causing mutation, the baseline status of the disease, the lifestyle and the diet of the patient. The long-term follow up of the patients with innovative orphan drugs is necessary to really understand the value of the treatment and the need of the patients.]

Clinical Neuroscience

MAY 30, 2020

Alexithymia is associated with cognitive impairment in patients with Parkinson’s disease

SENGUL Yildizhan, KOCAK Müge, CORAKCI Zeynep, SENGUL Serdar Hakan, USTUN Ismet

Cognitive dysfunction (CD) is a common non-motor symptom of Parkinson’s disease (PD). Alexithy­mia is a still poorly understood neuropsychiatric feature of PD. Cognitive impairment (especially visuospatial dysfunction and executive dysfunction) and alexithymia share com­mon pathology of neuroanatomical structures. We hypo­thesized that there must be a correlation between CD and alexithymia levels considering this relationship of neuroanatomy. Objective – The aim of this study was to evaluate the association between alexithymia and neurocognitive function in patients with PD. Thirty-five patients with PD were included in this study. The Toronto Alexithymia Scale–20 (TAS-20), Geriatric Depression Inventory (GDI) and a detailed neuropsychological evaluation were performed. Higher TAS-20 scores were negatively correlated with Wechsler Adult Intelligence Scale (WAIS) similarities test score (r =-0.71, p value 0.02), clock drawing test (CDT) scores (r=-0.72, p=0.02) and verbal fluency (VF) (r=-0.77, p<0.01). Difficulty identifying feelings subscale score was negatively correlated with CDT scores (r=-0.74, p=0.02), VF scores (r=-0.66, p=0.04), visual memory immediate recall (r=-0.74, p=0.01). VF scores were also correlated with difficulty describing feelings (DDF) scores (r=-0.66, p=0.04). There was a reverse relationship bet­ween WAIS similarities and DDF scores (r=-0.70, p=0.02), and externally oriented-thinking (r=-0.77,p<0.01). Executive function Z score was correlated with the mean TAS-20 score (r=-62, p=0.03) and DDF subscale score (r=-0.70, p=0.01) Alexithymia was found to be associated with poorer performance on visuospatial and executive function test results. We also found that alexithymia was significantly correlated with depressive symptoms. Presence of alexithymia should therefore warn the clinicians for co-existing CD.

Clinical Neuroscience

MAY 30, 2020

Autonomic nervous system may be affected after carpal tunnel syndrome surgery: A possible mechanism for persistence of symptoms after surgery

ONDER Burcu, KELES Yavuz Betul

After carpal tunnel surgery, some patients report complaints such as edema, pain, and numbness. Purpose – The aim of this study was to evaluate autonomic nervous system function in patients with a history of carpal tunnel surgery using sympathetic skin response (SSR). Thirty three patients (55 ±10 years old) with a history of unilateral operation for carpal tunnel syndrome were included in the study. The SSR test was performed for both hands. Both upper extremities median and ulnar nerve conduction results were recorded. A reduced amplitude (p=0.006) and delayed latency (p<0.0001) were detected in the SSR test on the operated side compared to contralateral side. There was no correlation between SSR and carpal tunnel syndrome severity. Although complex regional pain syndrome does not develop in patients after carpal tunnel surgery, some of the complaints may be caused by effects on the autonomic nervous system.

Clinical Neuroscience

JANUARY 30, 2016

[Event-related potentials and clinical symptoms in schizophrenia]

DOMJÁN Nóra, CSIFCSÁK Gábor, JANKA Zoltán

[The investigation of schizophrenia’s aetiology and pathomechanism is of high importance in neurosciences. In the recent decades, analyzing event-related potentials have proven to be useful to reveal the neuropsychological dysfunctions in schizophrenia. Even the very early stages of auditory stimulus processing are impaired in this disorder; this might contribute to the experience of auditory hallucinations. The present review summarizes the recent literature on the relationship between auditory hallucinations and event-related potentials. Due to the dysfunction of early auditory sensory processing, patients with schizophrenia are not able to locate the source of stimuli and to allocate their attention appropriately. These deficits might lead to auditory hallucinations and problems with daily functioning. Studies involving high risk groups may provide tools for screening and early interventions; thus improving the prognosis of schizophrenia. ]