Aysegul Gunduz1, Baris Metin2, Sinem Zeynep Metin3, Burc Cagri Poyraz4, Derya Karadeniz5, Gunes Kiziltan5, Meral E Kiziltan5. 1. Department of Neurology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey. Electronic address: draysegulgunduz@yahoo.com. 2. Department of Neurology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey; Department of Psychology, Uskudar University, Istanbul, Turkey. 3. Department of Psychiatry, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey; Department of Psychology, Uskudar University, Istanbul, Turkey. 4. Department of Psychiatry, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey. 5. Department of Neurology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey.
Abstract
BACKGROUND AND OBJECTIVE: Akathisia is characterized by restlessness and crawling sensations similar to restless legs syndrome (RLS). Long latency flexor reflex (LLFR) which has helped to advance RLS pathophysiology has never been investigated in akathisia. Due to the clinical commonalities of akathisia and RLS, we investigated the behavior of LLFR in patients with akathisia aiming to understand pathophysiology of akathisia. PATIENTS AND METHODS: Seven patients with neuroleptic-induced akathisia, 12 drug-naïve patients with primary RLS and 17 healthy subjects were prospectively enrolled in the study. LLFR was recorded from unilateral tibialis anterior (TA) and long head of biceps femoris (BF) muscles after stimulating the sole by trains of electrical stimuli. We measured amplitude, latency, duration, presence of response and compared between three groups. RESULTS: One-way ANOVA showed mean durations of early and late responses recorded over TA were the longest in akathisia group compared to both RLS group and healthy subjects (p=0.012). The spatial spread of LLFR in akathisia patients was comparable to those of healthy subjects whereas presence of response on BF was significantly less in akathisia than RLS group. CONCLUSIONS: Our findings indicate increased excitability of LLFR pathway in akathisia group. These findings are probably due to lack of inhibition originated in regions other than those known to downregulate in RLS.
BACKGROUND AND OBJECTIVE:Akathisia is characterized by restlessness and crawling sensations similar to restless legs syndrome (RLS). Long latency flexor reflex (LLFR) which has helped to advance RLS pathophysiology has never been investigated in akathisia. Due to the clinical commonalities of akathisia and RLS, we investigated the behavior of LLFR in patients with akathisia aiming to understand pathophysiology of akathisia. PATIENTS AND METHODS: Seven patients with neuroleptic-induced akathisia, 12 drug-naïve patients with primary RLS and 17 healthy subjects were prospectively enrolled in the study. LLFR was recorded from unilateral tibialis anterior (TA) and long head of biceps femoris (BF) muscles after stimulating the sole by trains of electrical stimuli. We measured amplitude, latency, duration, presence of response and compared between three groups. RESULTS: One-way ANOVA showed mean durations of early and late responses recorded over TA were the longest in akathisia group compared to both RLS group and healthy subjects (p=0.012). The spatial spread of LLFR in akathisiapatients was comparable to those of healthy subjects whereas presence of response on BF was significantly less in akathisia than RLS group. CONCLUSIONS: Our findings indicate increased excitability of LLFR pathway in akathisia group. These findings are probably due to lack of inhibition originated in regions other than those known to downregulate in RLS.