Pearls & Oy-sters: Paroxysmal dysarthria-ataxia syndrome

Paroxysmal dysarthria-ataxia syndrome

Paroxysmal dysarthria ataxia syndrome presents with recurrent, brief, stereotyped events of dysarthria, limb clumsiness, unsteady gait and vertigo or dizziness that can occur in association with lesions in the midbrain. We describe a case of a woman presenting with paroxysmal dysarthria and ataxia secondary to a midbrain lesion, treated successfully with carbamazepine.

A study on the correlations between acoustic speech variables and bradykinesia in advanced Parkinson's disease

Background

Very few studies have assessed the presence of a possible correlation between speech variables and limb bradykinesia in patients with Parkinson's disease (PD). The objective of this study was to find correlations between different speech variables and upper extremity bradykinesia under different medication conditions in advanced PD patients.

Methods

Retrospective data were collected from a cohort of advanced PD patients before and after an acute levodopa challenge. Each patient was assessed with a perceptual-acoustic analysis of speech, which included several quantitative parameters [i.e., maximum phonation time (MPT) and intensity (dB)]; the Unified Parkinson's Disease Rating Scale (UPDRS) (total scores, subscores, and items); and a timed test (a tapping test for 20 s) to quantify upper extremity bradykinesia. Pearson's correlation coefficient was applied to find correlations between the different speech variables and the tapping rate.

Results

A total of 53 PD patients [men: 34; disease duration: 10.66 (SD 4.37) years; age at PD onset: 49.81 years (SD 6.12)] were included. Levodopa intake increased the MPT of sustained phonation (p < 0.01), but it reduced the speech rate (p = 0.05). In the defined-OFF condition, MPT of sustained phonation positively correlated with both bilateral mean (p = 0.044, r-value:0.299) and left (p = 0.033, r-value:0.314) tapping. In the defined-ON condition, the MPT correlated positively with bilateral mean tapping (p = 0.003), left tapping (p = 0.003), and right tapping (p = 0.008).

Conclusion

This study confirms the presence of correlations between speech acoustic variables and upper extremity bradykinesia in advanced PD patients. These findings suggest common pathophysiological mechanisms.

Episodic Ataxias: Primary and Secondary Etiologies, Treatment, and Classification Approaches

Background

Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in KCNA1 and CACNA1A. EA3-8 are reported in rare families. Advances in genetic testing have broadened the KCNA1 and CACNA1A phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists.

Methods

A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized.

Results

EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (SCA-14, SCA-27, SCA-42, AOA2, CAPOS), epilepsy syndromes (KCNA2, SCN2A, PRRT2), GLUT-1, mitochondrial disorders (PDHA1, PDHX, ACO2), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause.

Discussion

EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.

Neuro‐Behcet's disease presenting as solitary midbrain lesion with paroxysmal ataxia and dysarthria (PAD) case report

Paroxysmal dysarthria and ataxia (PDA) is a rare neurological manifestation of stereotyped attacks of sudden ataxic symptoms lasts for few seconds to minutes. We report a case of PDA in a 61‐year‐old male with a solitary homogenously enhancing solitary midbrain lesion and positive HLA‐B51 (Allele 2), controlled with lacosamide.

Movement disorders in systemic autoimmune diseases: Clinical spectrum, ancillary investigations, pathophysiological considerations

With the advances in neuroimmunology especially due to the discovery of new neuronal antibodies, the recognition of treatable antibody-related movement disorders has recently received much attention. In contrast, the identification and characterisation of movement disorders associated with systemic autoimmune diseases remains a substantially unexplored area. Beyond the classic few associations such as chorea and antiphospholipid syndrome, or ataxia and coeliac disease, movement disorders have been reported in association with several systemic autoimmune diseases, however a clear image of clinical phenotypes, investigations, and treatment outcomes in these conditions has never been drawn. In this review, we analyse data from approximately 300 cases and summarise the epidemiological, clinical and diagnostic features of movement disorders associated with systemic autoimmune diseases, and the available knowledge about treatment and outcomes. We highlight that movement disorders in systemic autoimmune conditions are frequently the only or among a few presenting manifestations and are mostly treatable disorders responding to immunotherapy or dietary modifications. We point out the pertinent combination of clinical features and investigations which can suggest the underlying autoimmune nature of these movement disorders, and thus address the most appropriate treatment.

Paroxysmal dysarthria-ataxia syndrome: Literature review on MRI findings and report of a peculiar case with clinically isolated syndrome coexisting with anti-N-methyl-d-aspartate receptor antibodies

Paroxysmal dysarthria and ataxia (PDA) syndrome constitutes a rare neurological disorder, and is generally reported in cases of multiple sclerosis (MS) involving the midbrain. We present an illustrative case of 32-year-old female who developed clinically isolated syndrome manifested paroxysmal dysarthria, ataxia, ptosis and diplopia, coexisting with anti-N-methyl-d-aspartate receptor antibodies. We review the literature and identify 23 other cases with brain MRI examinations to summarize the lesion locations and clinical characteristics of PDA syndrome, and ultimately provide a new framework for understanding this rare condition. The current case expands the spectrum of symptoms in PDA syndrome, which was including but not limited to dysarthria and ataxia. Caudal paramedian midbrain lesions involving decussation of the superior cerebellar peduncles appear to be critical for PDA syndrome.