Surgical Outcomes in Rare Movement Disorders: A Report of Seventeen Patients from India and Review of Literature

Clinical neurophysiology in the treatment of movement disorders: IFCN handbook chapter

In this review, different aspects of the use of clinical neurophysiology techniques for the treatment of movement disorders are addressed. First of all, these techniques can be used to guide neuromodulation techniques or to perform therapeutic neuromodulation as such. Neuromodulation includes invasive techniques based on the surgical implantation of electrodes and a pulse generator, such as deep brain stimulation (DBS) or spinal cord stimulation (SCS) on the one hand, and non-invasive techniques aimed at modulating or even lesioning neural structures by transcranial application. Movement disorders are one of the main areas of indication for the various neuromodulation techniques. This review focuses on the following techniques: DBS, repetitive transcranial magnetic stimulation (rTMS), low-intensity transcranial electrical stimulation, including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), and focused ultrasound (FUS), including high-intensity magnetic resonance-guided FUS (MRgFUS), and pulsed mode low-intensity transcranial FUS stimulation (TUS). The main clinical conditions in which neuromodulation has proven its efficacy are Parkinson's disease, dystonia, and essential tremor, mainly using DBS or MRgFUS. There is also some evidence for Tourette syndrome (DBS), Huntington's disease (DBS), cerebellar ataxia (tDCS), and axial signs (SCS) and depression (rTMS) in PD. The development of non-invasive transcranial neuromodulation techniques is limited by the short-term clinical impact of these techniques, especially rTMS, in the context of very chronic diseases. However, at-home use (tDCS) or current advances in the design of closed-loop stimulation (tACS) may open new perspectives for the application of these techniques in patients, favored by their easier use and lower rate of adverse effects compared to invasive or lesioning methods. Finally, this review summarizes the evidence for keeping the use of electromyography to optimize the identification of muscles to be treated with botulinum toxin injection, which is indicated and widely performed for the treatment of various movement disorders.

Estimation of Ambulation and Survival in Neurodegeneration with Brain Iron Accumulation Disorders

BACKGROUND

Neurodegeneration with Brain Iron Accumulation (NBIA) disorder is a group of ultra-orphan hereditary diseases with very limited data on its course.

OBJECTIVES

To estimate the probability of preserving ambulatory ability and survival in NBIA.

METHODS

In this study, the electronic records of the demographic data and clinical assessments of NBIA patients from 2012 to 2023 were reviewed. The objectives of the study and factors impacting them were investigated by Kaplan-Meier and Cox regression methods.

RESULTS

One hundred and twenty-two genetically-confirmed NBIA patients consisting of nine subtypes were enrolled. Twenty-four and twenty-five cases were deceased and wheelchair-bound, with a mean disease duration of 11 ± 6.65 and 9.32 ± 5 years. The probability of preserving ambulation and survival was 42.9% in 9 years and 28.2% in 15 years for classical Pantothenate Kinase-Associated Neurodegeneration (PKAN, n = 18), 89.4% in 7 years and 84.7% in 9 years for atypical PKAN (n = 39), 23% in 18 years and 67.8% in 14 years for Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN, n = 23), 75% in 20 years and 36.5% in 33 years for Kufor Rakeb Syndrome (KRS, n = 17), respectively. The frequencies of rigidity, spasticity, and female gender were significantly higher in deceased cases compared to surviving patients. Spasticity was the only factor associated with death (P value = 0.03).

CONCLUSIONS

KRS had the best survival with the most extended ambulation period. The classical PKAN and MPAN cases had similar progression patterns to loss of ambulation ability, while MPAN patients had a slower progression to death. Spasticity was revealed to be the most determining factor for death.

Clinical Spectrum, Radiological Correlation and Outcome of Movement Disorders in Wilson's Disease

Introduction

Movement disorders are the commonest clinical presentation in patients with neurological Wilson's disease (NWD). There are very few studies evaluating the spectrum, severity and their correlation with magnetic resonance imaging (MRI) changes of movement disorders in NWD.

Objective

To study the spectrum, topographic distribution, radiological correlate, temporal course and outcome in our cohort of NWD patients.

Methods

Retrospective chart review of the NWD patients having movement disorders was performed and analyzed.

Results

Sixty-nine patients (males- 47) with NWD were analysed and the mean age at the onset of neurological symptoms was 13.6 ± 6.6 years (median 13 years; range 7-37 years). The first neurological symptom was movement disorder in 55 (79.7%) patients. Tremor (43.6%) and dystonia (41.8%) was the commonest movement disorder as the first neurological symptom. Dystonia (76.8%) was the most common overall movement disorder followed by parkinsonism (52.1%) and tremors (47.8%). Chorea (10.1%), myoclonus (1.4%) and ataxia (1.4%) were the least common movement disorder. Putamen was the most common affected site (95.6%) followed by caudate nucleus (73.9%), thalamus (60.8%), midbrain (59.4%), internal capsule (49.2%), pons (46.3%). Putamen was the most common area of abnormality in dystonia (98%), tremors (85%). Caudate (75%) and putamen (75%) was the most common areas of abnormality in parkinsonism. Favourable outcome was observed in 42 patients (60.8%) following treatment.

Conclusion

Dystonia is the most common movement disorder in NWD in isolation or in combination with parkinsonism and tremors. Putamen is the most common radiological site of lesions and more frequently affected in patients with dystonia and tremors. Favourable outcome does occur with appropriate medical and surgical treatment.

Tackling the neurological manifestations in Wilson's disease - currently available treatment options

INTRODUCTION

Wilson's disease (WD) is a potentially treatable, inherited disorder resulting from impaired copper metabolism. Pathological copper accumulation causes a range of symptoms, most commonly hepatic and a wide spectrum of neurological symptoms including tremor, dystonia, chorea, parkinsonism, dysphagia, dysarthria, gait and posture disturbances. To reduce copper overload, anti-copper drugs are used that improve liver function and neurological symptoms in up to 85% of patients. However, in some WD patients, treatment introduction leads to neurological deterioration, and in others, neurological symptoms persist with no improvement or improvement only after several years of treatment, severely affecting the patient's quality of life.

AREAS COVERED

This review appraises the evidence on various pharmacological and non-pharmacological therapies, neurosurgical procedures and liver transplantation for the management of neurological WD symptoms. The authors also discuss the neurological symptoms of WD, causes of deterioration and present symptomatic treatment options.

EXPERT OPINION

Based on case and series reports, current recommendations and expert opinion, WD treatment is focused mainly on drugs leading to negative copper body metabolism (chelators or zinc salts) and copper-restricted diet. Treatment of WD neurological symptoms should follow general recommendations of symptomatic treatment. Patients should be always considered individually, especially in the case of severe, disabling neurological symptoms.

Surgical treatment of movement disorders in neurometabolic conditions

Refractory movement disorders are a common feature of inborn errors of metabolism (IEMs), significantly impacting quality of life and potentially leading to life-threatening complications such as status dystonicus. Surgical techniques, including deep brain stimulation (DBS) and lesioning techniques, represent an additional treatment option. However, the application and benefits of these procedures in neurometabolic conditions is not well understood. This results in challenges selecting surgical candidates and counseling patients preoperatively. In this review, we explore the literature of surgical techniques for the treatment of movement disorders in IEMs. Globus pallidus internus DBS has emerged as a beneficial treatment option for dystonia in Panthotate-Kinase-associated Neurodegeneration. Additionally, several patients with Lesch-Nyhan Disease have shown improvement following pallidal stimulation, with more robust effects on self-injurious behavior than dystonia. Although there are numerous reports describing benefits of DBS for movement disorders in other IEMs, the sample sizes have generally been small, limiting meaningful conclusions. Currently, DBS is preferred to lesioning techniques. However, successful use of pallidotomy and thalamotomy in neurometabolic conditions has been reported and may have a role in selected patients. Surgical techniques have also been used successfully in patients with IEMs to treat status dystonicus. Advancing our knowledge of these treatment options could significantly improve the care for patients with neurometabolic conditions.

Clinical, imaging and genetic profile of twenty-four patients with pantothenate kinase-associated neurodegeneration (PKAN)- A single centre study from India

INTRODUCTION

Pantothenate kinase-associated neurodegeneration (PKAN) is the most common "Neurodegeneration with Brain Iron Accumulation" disorder. This study aimed to study the clinical, radiological and genetic profiling of a large cohort of patients with PKAN.

METHODS

This is an ambispective hospital-based single centre study conducted at a tertiary care centre from India. After tabulating the clinical details, appropriate rating scales were applied followed by magnetic resonance imaging brain and exome sequencing. The segregation of the causal variants in the families were analysed using Sanger sequencing.

RESULTS

Twenty-four patients (14 males) with a median age at initial examination of 13 years (range: 4-54 years) and age at onset of 8 years (range: 0.5-40 years) were identified. Almost two-thirds (62%) had onset before 10 years. Difficulty walking was the most common presenting symptom (41.6%) and dystonia was the most common extrapyramidal phenomenology (100%) followed by parkinsonism (54.2%). Retinitis pigmentosa was present in 37.5% patients. MRI showed hypo intensity on T2 and SWI sequences in globus pallidus (100%), substantia nigra (70.8%) and red nucleus (12.5%). Eye-of-the-tiger sign was present in 95.8%. Biallelic variants in PANK2 gene was identified in all 20 patients who underwent genetic testing. Among the 18 unique variants identified in these 20 patients 10 were novel. Sanger sequencing confirmed the segregation of the mutation in the available family members.

CONCLUSIONS

Wide range of age at onset was noted. Dystonia at presentation, pathognomonic eye-of-tiger sign, and disease-causing variants in PANK2 gene were identified in nearly all patients. Ten novel variants were identified expanding the genotypic spectrum of PKAN.