TY - JOUR

T1 - Episodic ataxia type 2 (EA2) with interictal myokymia and focal dystonia

AU - Nielsen, Emilie Neerup

AU - Ásbjörnsdóttir, Birna

AU - Møller, Lisbeth Birk

AU - Nielsen, Jørgen Erik

AU - Lindquist, Suzanne Granhøj

N1 - Publisher Copyright: © 2022 Nielsen et al.; Published by Cold Spring Harbor Laboratory Press.

PY - 2022

Y1 - 2022

N2 - Episodic ataxia type 1 and 2 (EA1 and EA2) are the most well-described of the episodic ataxias. They are autosomal dominantly inherited early-onset diseases characterized by attacks of cerebellar dysfunction. EA1 is clinically characterized by short episodes of ataxia with interictal myokymia, whereas EA2 is characterized by longer-lasting recurrent ataxia, slurred speech, and interictal nystagmus. We report on a patient with EA2 with interictal focal dystonia and also interictal myokymia, which is hitherto not reported as an interictal feature associated to EA2. The patient carries a previously described heterozygous pathogenic de novo frameshift variant in the CACNA1A gene, establishing the diagnosis of EA2. She had symptom onset at age 13 and from age 48 she developed interictal myokymia and focal dystonia as illustrated in Supplemental Movie S1. We conclude that interictal myokymia and focal dystonia may be interictal features associated to EA2 caused by the cerebellar pathophysiology of EA2. Episodes of ataxia were successfully treated with acetazolamide in low dose, whereas the interictal features were unresponsive to acetazolamide.

AB - Episodic ataxia type 1 and 2 (EA1 and EA2) are the most well-described of the episodic ataxias. They are autosomal dominantly inherited early-onset diseases characterized by attacks of cerebellar dysfunction. EA1 is clinically characterized by short episodes of ataxia with interictal myokymia, whereas EA2 is characterized by longer-lasting recurrent ataxia, slurred speech, and interictal nystagmus. We report on a patient with EA2 with interictal focal dystonia and also interictal myokymia, which is hitherto not reported as an interictal feature associated to EA2. The patient carries a previously described heterozygous pathogenic de novo frameshift variant in the CACNA1A gene, establishing the diagnosis of EA2. She had symptom onset at age 13 and from age 48 she developed interictal myokymia and focal dystonia as illustrated in Supplemental Movie S1. We conclude that interictal myokymia and focal dystonia may be interictal features associated to EA2 caused by the cerebellar pathophysiology of EA2. Episodes of ataxia were successfully treated with acetazolamide in low dose, whereas the interictal features were unresponsive to acetazolamide.

KW - episodic ataxia

U2 - 10.1101/mcs.a006236

DO - 10.1101/mcs.a006236

M3 - Journal article

C2 - 36307210

AN - SCOPUS:85141004208

VL - 8

JO - Cold Spring Harbor molecular case studies

JF - Cold Spring Harbor molecular case studies

SN - 2373-2865

IS - 6

M1 - a006236

ER -