Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Neurol Sci. 2010 May 15;292(1-2):81-4. doi: 10.1016/j.jns.2010.01.021. Epub 2010 Feb 23.
Downbeat nystagmus (DBN) is often seen in patients with pure cerebellar type of spinocerebellar ataxia (SCA) like spinocerebellar ataxia type 6 (SCA6). DBN frequently presents with other cerebellar symptoms such as postural imbalance or ataxia. A potassium channel blocker 3,4-diaminopyridine (3,4-DAP) has been reported to reduce DBN by increasing the excitability of Purkinje cells.
The objective of this study is to determine whether 3,4-DAP has a beneficial effect on DBN along with postural imbalance and ataxic symptoms in 10 patients with SCA6 and five patients with chromosome 16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA).
The patients took 20mg of 3,4-DAP twice a day for a week. DBN was observed in seven patients with SCA6 and two with 16q-ADCA. Although 3,4-DAP significantly reduced DBN (P<0.05), other ataxic symptoms did not improved. However, 3,4-DAP showed benefit in two patients with oscillopsia.
3,4-DAP may be effective on DBN and oscillopsia, although it was not proved to be effective on other symptoms of ataxia in SCA patients.
下跳性眼球震颤（DBN）常发生于纯小脑型脊髓小脑共济失调（SCA）患者，如 SCA6。DBN 常伴有姿势平衡障碍或共济失调等其他小脑症状。钾通道阻滞剂 3,4-二氨基吡啶（3,4-DAP）可通过增加浦肯野细胞的兴奋性来减少 DBN。
本研究旨在确定 3,4-DAP 是否对 10 例 SCA6 患者和 5 例 16q22.1 连锁常染色体显性小脑共济失调（16q-ADCA）患者的 DBN 以及姿势平衡障碍和共济失调症状有有益作用。
患者每天服用 3,4-DAP 20mg，分两次服用，持续一周。7 例 SCA6 患者和 2 例 16q-ADCA 患者出现 DBN。尽管 3,4-DAP 显著减少了 DBN（P<0.05），但其他共济失调症状并未改善。然而，3,4-DAP 对 2 例眼球震颤患者有效。
3,4-DAP 可能对 SCA 患者的 DBN 和眼球震颤有效，尽管它对其他共济失调症状的疗效尚未得到证实。
