Long-term improvement of paroxysmal dystonic choreathetosis with acetazolamide

Differentiating non-epileptic seizures from epileptic seizures in Glut1 deficiency syndrome

AIM

To investigate the clinical characteristics of non-epileptic seizures due to transient brain dysfunction caused by energy deficiency after prolonged fasting or exercise in individuals with glucose transporter type 1 deficiency syndrome (Glut1DS), and then elucidate further the seizure features to distinguish non-epileptic seizures from epileptic seizures.

METHOD

This retrospective case-control study included 57 non-epileptic seizures and 23 epileptic seizures (control group) in 14 individuals (11 males, three females; aged 5-44 years, median = 20 years) with Glut1DS, all with a heterozygous pathogenic SLC2A1 mutation.

RESULTS

Non-epileptic seizures were classified as paroxysmal altered consciousness (n = 8), movement disorders (n = 35) (eye-head movements, ataxia, spasticity, weakness, involuntary movement), dysaesthesia (n = 8), and vomiting (n = 6) at the peak ages at onset of 5 to 10 years. Ketogenic diet therapy was effective in 33 of 43 (77%) non-epileptic seizures. Providing supplementary food before high-impact exercise or during attacks prevented or mitigated non-epileptic seizures in some individuals. Glut1DS-associated non-epileptic seizures are fundamentally situation-related seizures with specific provoking and ameliorating factors. Non-epileptic seizures can be distinguished from epileptic seizures by the absence of complete consciousness loss and rapid postictal recovery despite prolonged seizures.

INTERPRETATION

Non-epileptic seizures are not well recognized but require different therapeutic approaches compared to epileptic seizures. Awareness of the differentiation of non-epileptic seizures from epileptic seizures is essential when performing preventive or therapeutic decision-making for acute exacerbation seizures.

WHAT THIS PAPER ADDS

Non-epileptic seizures are invariably situation-related seizures. Non-epileptic seizures were classified as altered consciousness, movement disorders, dysaesthesia, and vomiting. Non-epileptic seizures were characterized by the absence of complete consciousness loss and were accompanied by rapid recovery. Non-epileptic seizures can occur simultaneously or consecutively with another. Supplementary food can be effective in preventing the development of sustained exercise-induced movement disorders.

Paroxysmal movement disorders: An update

Paroxysmal movement disorders comprise both paroxysmal dyskinesia, characterized by attacks of dystonic and/or choreic movements, and episodic ataxia, defined by attacks of cerebellar ataxia. They may be primary (familial or sporadic) or secondary to an underlying cause. They can be classified according to their phenomenology (kinesigenic, non-kinesigenic or exercise-induced) or their genetic cause. The main genes involved in primary paroxysmal movement disorders include PRRT2, PNKD, SLC2A1, ATP1A3, GCH1, PARK2, ADCY5, CACNA1A and KCNA1. Many cases remain genetically undiagnosed, thereby suggesting that additional culprit genes remain to be discovered. The present report is a general overview that aims to help clinicians diagnose and treat patients with paroxysmal movement disorders.

Effect of acetazolamide for long-lasting paroxysmal dystonia in a patient with multiple sclerosis: a case report and review of literature

Dystonia is a rare manifestation of multiple sclerosis (MS), but it always interferes with the functional performance and quality of life. We report a rare case of long-lasting paroxysmal dystonia associated with MS. The patient was a 40-year-old woman with relapsing- remitting MS for 6 years. During the latest attack of MS, she suffered from long-lasting paroxysmal dystonia in her left hand. Despite treatment with pulse high-dose intravenous methylprednisolone, interferon, and baclofen, along with occupational therapy, the dystonia persisted and significantly bothered her daily activities. Finally, she was treated with oral acetazolamide (250 mg, three times a day for 4 days), which was very effective for the control of her dystonia. The dystonic movement subsided without recurrence in a follow-up of 17 months. We advocate this effective and safe treatment for patients with paroxysmal dystonia associated with MS.

Characterization and mode of inheritance of a paroxysmal dyskinesia in Chinook dogs

BACKGROUND

Paroxysmal dyskinesias are episodes of abnormal, involuntary movement or muscle tone, distinguished from seizures by the character of the episode and lack of seizure activity on ictal EEG.

HYPOTHESIS

Paroxysmal dyskinesia is an inherited, autosomal recessive disorder in Chinook dogs.

ANIMALS

Families of Chinook dogs with paroxysmal dyskinesia.

METHODS

Pedigrees and medical histories were reviewed for 299 Chinook dogs. A family of 51 dogs was used for analysis. Episodes were classified as seizures, paroxysmal dyskinesia, or unknown, and segregation analysis was performed.

RESULTS

Paroxysmal dyskinesia was identified in 16 of 51 dogs and characterized by an inability to stand or ambulate, head tremors, and involuntary flexion of 1 or multiple limbs, without autonomic signs or loss of consciousness. Episode duration varied from minutes to an hour. Inter-ictal EEGs recorded on 2 dogs with dyskinesia were normal. Three dogs with dyskinesia also had generalized tonic-clonic seizures. One of 51 dogs had episodes of undetermined type. Phenotype was unknown for 6 of 51 dogs, and 28 dogs were unaffected. Segregation was consistent with an autosomal recessive trait.

CONCLUSIONS AND CLINICAL IMPORTANCE

This movement disorder is prevalent in the Chinook breed, and consistent with a partially penetrant autosomal recessive or polygenic trait. Insufficient evidence exists for definitive localization; episodes may be of basal nuclear origin, but atypical seizures and muscle membrane disorders remain possible etiologies. The generalized seizures may be a variant phenotype of the same mutation that results in dyskinesia, or the 2 syndromes may be independent.