[Essential tremor: update]

Bilateral globus pallidus interna deep brain stimulation in the treatment of mixed cerebral palsy in ataxia with dyskinesia: a case report

Background

Cerebral palsy (CP), a complex syndrome with multiple etiologies, is characterized by a range of movement disorders within the hypokinetic and hyperkinetic spectrum (dystonia or choreoathetosis). CP is often accompanied by neurological and psychiatric signs, such as spasticity, ataxia, and cognitive disorders. Although current treatment options for CP include pharmacological interventions, rehabilitation programs, and spasticity relief surgery, their effectiveness remains limited. Deep brain stimulation (DBS) has demonstrated significant effectiveness in managing dyskinesia; however, its potential therapeutic effect on CP remains determined.

Methods

We present a case of a 44-year-old Asian female who was born as a twin with neonatal ischemic-hypoxic encephalopathy due to prolonged labor and delivery. She was diagnosed with CP at the age of 1 year. The patient exhibited delayed development compared to her peers and presented with various symptoms, including slurred speech, broad-based gait, horseshoe inversion of the right lower extremity, involuntary shaking of the upper extremities bilaterally, and hypotonia and showed no improvement with levodopa therapy. Two years ago, she developed progressive head tremors, which worsened during periods of tension and improved during sleep. As medical treatments proved ineffective and there were no contraindications to surgery, we performed bilateral globus pallidus interna DBS (GPi-DBS) to alleviate her motor dysfunction.

Results

Following a 6-month follow-up, the patient demonstrated significant improvements in motor symptoms, including head and limb tremors and dystonia. In addition, significant improvement was observed in her overall psychological well-being, as evidenced by reduced anxiety and depression levels.

Conclusion

DBS is an effective treatment for dyskinesia symptoms associated with CP in adults. Moreover, its effectiveness may continue to increase over time.

Essential tremor: a neurodegenerative disease?

Background

Essential tremor (ET) is one of the most common neurological disorders among adults, and is the most common of the many tremor disorders. It has classically been viewed as a benign monosymptomatic condition, yet over the past decade, a growing body of evidence indicates that ET is a progressive condition that is clinically heterogeneous, as it may be associated with a spectrum of clinical features, with both motor and non-motor elements. In this review, I will describe the most significant emerging milestones in research which, when taken together, suggest that ET is a neurodegenerative condition.

Methods

A PubMed search conducted in June 2014 crossing the terms “essential tremor” (ET) and “neurodegenerative” yielded 122 entries, 20 of which included the term “neurodegenerative” in the article title. This was supplemented by articles in the author's files that pertained to this topic.

Results/Discussion

There is an open and active dialogue in the medical community as to whether ET is a neurodegenerative disease, with considerable evidence in favor of this. Specifically, ET is a progressive disorder of aging associated with neuronal loss (reduction in Purkinje cells) as well as other post-mortem changes that occur in traditional neurodegenerative disorders. Along with this, advanced neuroimaging techniques are now demonstrating distinct structural changes, several of which are consistent with neuronal loss, in patients with ET. However, further longitudinal clinical and neuroimaging longitudinal studies to assess progression are required.

Rate of cognitive decline during the premotor phase of essential tremor: a prospective study

OBJECTIVE

To characterize the rate of cognitive decline during the premotor phase of essential tremor (ET) in comparison to prevalent ET cases and controls.

METHODS

In this population-based, prospective study of people aged 65 years and older (Neurological Disorders in Central Spain), a 37-item version of the Mini-Mental State Examination was administered at 2 visits (baseline and follow-up, approximately 3 years later). We compared the rate of cognitive decline in 3 groups: prevalent ET cases (i.e., participants diagnosed with ET at baseline and at follow-up), "premotor" ET cases (i.e., participants diagnosed with incident ET at follow-up, but not at baseline), and controls (i.e., participants not diagnosed with ET at baseline or follow-up).

RESULTS

The 2,375 participants included 135 prevalent ET cases, 56 premotor ET cases, and 2,184 controls. During the follow-up period of 3.4 ± 0.5 years (mean ± SD), the 37-item version of the Mini-Mental State Examination declined by 0.7 ± 3.3 points (0.2 ± 1.0 points/year) in prevalent ET cases, 1.1 ± 3.5 points (0.3 ± 1.0 points/year) in premotor ET cases, and 0.1 ± 3.9 points (0.0 ± 1.2 points/year) in controls (p = 0.014). The difference between premotor ET cases and controls was significant (p = 0.046), as was the difference between prevalent ET cases and controls (p = 0.027).

CONCLUSIONS

In this prospective cohort, cognitive test scores in premotor and prevalent ET cases declined at a faster rate than in elders without this disease. A decline in global cognitive function may occur in a premotor phase of ET.