Functional eye movement disorders

Eye Movement Disorders in Movement Disorders

Oculomotor assessment is an essential element of the neurological clinical examination and is particularly important when evaluating patients with movements disorders. Most of the brain is involved in oculomotor control, and thus many neurological conditions present with oculomotor abnormalities. Each of the different classes of eye movements and their features can provide important information that can facilitate differential diagnosis. This educational review presents a clinical approach to eye movement abnormalities that are commonly seen in parkinsonism, ataxia, dystonia, myoclonus, tremor, and chorea. In parkinsonism, subtle signs such as prominent square wave jerks, impaired vertical optokinetic nystagmus, and/or the "round the houses" sign suggest early progressive supranuclear gaze palsy before vertical gaze is restricted. In ataxia, nystagmus is common, but other findings such as oculomotor apraxia, supranuclear gaze palsy, impaired fixation, or saccadic pursuit can contribute to diagnoses such as ataxia with oculomotor apraxia, Niemann-Pick type C, or ataxia telangiectasia. Opsoclonus myoclonus and oculopalatal myoclonus present with characteristic phenomenology and are usually easy to identify. The oculomotor exam is usually unremarkable in isolated dystonia, but oculogyric crisis is a medical emergency and should be recognized and treated in a timely manner. Gaze impersistence in a patient with chorea suggests Huntington's disease, but in a patient with dystonia or tremor, Wilson's disease is more likely. Finally, functional eye movements can reinforce the clinical impression of a functional movement disorder.

Periorbital injections of botulinum toxin a: a novel therapeutic option for convergence spasm in neuropsychiatric disorders

PURPOSE

Convergence spasm (CS, spasm of near reflex) is characterized by transient attacks of convergence, miosis and accommodation, often associated with functional neurological disorders. To date, no simple and efficient treatment option is available for CS. This study investigates whether periorbital botulinum toxin injections as used in essential blepharospasm are also a treatment option in these patients.

METHODS

All patients with convergence spasm having been treated with periorbital BoNTA injections in the department of neuro-ophthalmology were identified. Data were extracted from patient files concerning details and subjective effectiveness of botulinum toxin injections and relation to psychiatric or neurological disorders. Patients reporting with a history of closed-head trauma or organic neurologic pathologies possibly causing CS were excluded. A telephone assessment with a standardized questionnaire was performed to evaluate mental health issues as a trigger, as well as the long-term effect and satisfaction with periorbital injections.

RESULTS

Of 16 patients treated with periorbital botulinum toxin injections for convergence spasm, 9 patients reported depression and/or anxiety disorders ongoing or in the past. A median number of 3 injections (range 1-13) was administered with a variable effect (relief of symptoms) between no effect and effect of up to more than 12 weeks. A longitudinal follow-up revealed ongoing symptoms in five patients.

CONCLUSIONS

Periorbital botulinum toxin injections are less invasive than injections in the medial rectus muscle and can be a bridging therapeutic option in patients with CS. Mental health exploration is important due to psychiatric comorbidity.

Drug-induced maculopathy

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of drug-induced maculopathies including their clinical presentations, diagnostic findings, and treatment options. With the increasing pace of development and arrival of drugs to the market, this review aims to inform retina specialists of relevant side effects that may be encountered in a clinical practice setting.

RECENT FINDINGS

The major themes visited in this article focus on relevant findings of drugs that cause pigmentary and crystalline maculopathy, photoreceptor dysfunction, cystoid macular edema, central serous choroidopathy, uveitis, and vascular damage.

SUMMARY

The current review reports updated findings and discusses the pathophysiologic mechanisms, presentations, and treatments of drug-induced maculopathies.

Functional positional eye and eyelid movements

BACKGROUND

Positional manoeuvres are an important part of the neurological examination, particularly in patients with vertigo where the presence and characteristics of provoked nystagmus can help differentiate central from peripheral neurological disorders.

METHODS

Case series of functional positional eye and eyelid movements.

RESULTS

We report four patients with functional eye and eyelid movements provoked during positional manoeuvres. The range of abnormalities observed included positional convergence spasm, brief functional saccadic oscillations, and excessive positional blinking mimicking upbeat nystagmus. The functional movements described were present on a background of pre-existing peripheral or central nystagmus, or positional vertigo.

CONCLUSION

Functional positional eye and eyelid movements may co-exist with organic nystagmus that renders an accurate interpretation of the manoeuvre more challenging. A thorough understanding of the clinical features that differentiate these two categories of eye/eyelid movements makes the analysis easier, thus preventing misdiagnosis and avoiding unnecessary investigations.

Abnormal Eye and Cranial Movements Triggered by Examination in People with Functional Neurological Disorder

The diagnosis of functional neurological disorder (FND) relies on the demonstration of positive symptoms and signs, as supported by recent changes in DSM5. We recorded the findings of routine clinical eye movement assessment in 101 consecutive new patients with FND. Clinical examination triggered facial and eye movement disorders in 46% of patients, all with positive characteristics of functional movement disorder. These are useful as supporting features in making a positive diagnosis of FND.

Are Patients with Psychogenic Movement Disorders More Likely to be Healthcare Workers?

Background

Reported risk factors for the development of a psychogenic movement disorder (PMD) include young age, female gender, history of abuse, current or past psychiatric disorder, lower levels of education and socioeconomic status, and employment as a healthcare worker. Although employment in healthcare is included in several diagnostic criteria for PMD, as well as in many case series, this association has never been validated.

Methods

Using the University of Maryland Movement Disorder Database (UMMDD), we identified PMD cases, as well as patients with isolated focal dystonia as controls. An experienced movement disorder specialist diagnosed all patients, and all cases met criteria for clinically established PMD. Demographic and occupational histories were obtained from medical records and were supplemented by telephone interviews. PMD cases and controls were compared using t tests/χ² tests.

Results

Controls (n = 148) were older than PMD cases (n = 132), with an average age of 61.4 and 52.1 years, respectively (P < 0.001); there were no significant differences between groups with respect to gender, education level, and ethnicity. The proportion of healthcare workers was not significantly different between PMD cases and controls (25% of PMD cases vs. 20% of controls; P = 0.28).

Conclusions

In contrast to traditional teaching, this investigation demonstrates that in our patient population, patients with a PMD were no more likely to be employed as healthcare workers than patients with isolated focal dystonia. This study calls into question the use of employment in healthcare as a reliable criterion to support the diagnosis of PMD.