A case of micrographia after subcortical infarction: possible involvement of frontal lobe function

Using computerized spiral analysis to evaluate deep brain stimulation outcomes in Parkinson disease

OBJECTIVE

To determine whether spiral analysis can monitor the effects of deep brain stimulation (DBS) in Parkinson disease (PD) and provide a window on clinical features that change post-operatively. Clinical evaluation after DBS is subjective and insensitive to small changes. Spiral analysis is a computerized test that quantifies kinematic, dynamic, and spatial aspects of spiral drawing. Validated computational indices are generated and correlate with a range of clinically relevant motor findings. These include measures of overall clinical severity (Severity), bradykinesia and rigidity (Smoothness), amount of tremor (Tremor), irregularity of drawing movements (Variability), and micrographia (Tightness).

METHODS

We retrospectively evaluated the effect of subthalamic nucleus (STN) (n = 66) and ventral intermediate thalamus (Vim) (n = 10) DBS on spiral drawing in PD subjects using spiral analysis. Subjects freely drew ten spirals on plain paper with an inking pen on a graphics tablet. Five spiral indices (Severity, Smoothness, Tremor, Variability, Tightness) were calculated and compared pre- and post-operatively using Wilcoxon-rank sum tests, adjusting for multiple comparisons.

RESULTS

Severity improved after STN and Vim DBS (p < 0.005). Smoothness (p < 0.01) and Tremor (p < 0.02) both improved after STN and Vim DBS. Variability improved only with Vim DBS. Neither STN nor Vim DBS significantly changed Tightness.

CONCLUSIONS

All major spiral indices, except Tightness, improved after DBS. This suggests spiral analysis monitors DBS effects in PD and provides an objective window on relevant clinical features that change post-operatively. It may thus have utilization in clinical trials or investigations into the neural pathways altered by DBS. The lack of change in Tightness supports the notion that DBS does not improve micrographia.

Permanent isolated micrographia from traumatic basal ganglia injury

Micrographia is a rare neurological finding in isolation. Most cases of isolated micrographia have been found in association with focal ischemia of the left basal ganglia. Here, we present a case of post-traumatic micrographia stemming from contusion to the left basal ganglia.

Micrographia, much beyond the writer's hand

INTRODUCTION

This review on micrographia aims to draw the clinician's attention to non-Parkinsonian etiologies, provide clues to differential diagnosis, and summarize current knowledge on the phenomenology, etiology, and mechanisms underlying micrographia.

METHODS

A systematic review of the existing literature was performed.

RESULTS

Micrographia, namely small sized handwriting has long been attributed to Parkinson's disease. However, it has often been observed as part of the clinical picture of additional neurodegenerative disorders, sometimes antedating the motor signs, or following focal basal ganglia lesions without any accompanying parkinsonism, suggesting that bradykinesia and rigidity are not sine-qua-non for the development of this phenomenon. Therefore, micrographia in a patient with no signs of parkinsonism may prompt the clinician to perform imaging in order to exclude a focal basal ganglia lesion. Dopaminergic etiology in this and other cases is doubtful, since levodopa ameliorates letter stroke size only partially, and only in some patients. Parkinsonian handwriting is often characterized by lack of fluency, slowness, and less frequently by micrographia. Deviations from kinematic laws of motion that govern normal movement, including the lack of movement smoothness and inability to scale movement amplitude to the desired size, may reflect impairments in motion planning, possible loss of automaticity and reduced movement vigor.

CONCLUSIONS

The etiology, neuroanatomy, mechanisms and models of micrographia are discussed. Dysfunction of the basal ganglia circuitry induced by neurodegeneration or disruption by focal damage give rise to micrographia.

An Atypical Case of Anti-NMDA Receptor Encephalitis: Predominant Parkinsonism and Persisting Micrographia without Oro-facial Dyskinesia

We describe the case of a 46-year-old man with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis with prominent parkinsonism. The patient presented with psychiatric symptoms followed by epileptic seizure and parkinsonism including micrographia. Magnetic resonance imaging (MRI) revealed lesions in the bilateral medial temporal lobes and basal ganglia on fluid-attenuated inversion recovery images. His symptoms and MRI findings were ameliorated by immunotherapy but then relapsed. After retreatment, his parkinsonism gradually improved except for the micrographia. This is an atypical case of anti-NMDAR encephalitis in that the patient showed prominent and refractory parkinsonism, thus indicating that the clinical diversity of anti-NMDAR encephalitis is greater than expected.

Fast micrographia: An unusual but distinctive sign

Fast micrographia is a rare clinical sign, which is reported in patients with pallidal pathology. A 68-year-old male presented with hypophonia and short shuffling gait with decreased arm swing. About 3 weeks before, he had an acute myocardial infarction and a period of hemodynamic and respiratory distress during which he required mechanical ventilatory support. He was found to have a fast handwriting with micrographia from the outset. His rapid alternating hand and finger movements were normal. Magnetic resonance imaging (MRI) of the brain showed features of hypoxic ischemic encephalopathy including hyperintensities on T1 and T2 weighted images in the globus pallidus, and putamen bilaterally.

Micrographia and related deficits in Parkinson's disease: a cross-sectional study

OBJECTIVES

To determine the prevalence and clinical features associated with micrographia in Parkinson's Disease (PD).

SETTING

This study was conducted at a Movement Disorders clinic located in a Veteran Administration Hospital.

PARTICIPANTS

PD subjects were included only if they satisfied UK Parkinson's Disease Society criteria for diagnosis. Subjects with history of severe tremors, dystonia, dyskinesia, strokes, peripheral neuropathy and dementia were excluded.

DESIGN

This was a case-control study where PD subjects were prospectively enrolled and their demographics, Hoehn & Yahr stage, Unified Parkinson's Disease Rating Scale and Mini Mental Status examination (MMSE) scores were recorded. All subjects were specifically asked for micrographia on history and the handwritings were quantitatively documented. Bradykinesia was determined by history and quantified by a finger tap, Purdue pegboard and a timed walk test. Similarly, hypophonia was determined by history and the volume of speech quantified using a decibel meter. Controls were enrolled for validation of handwriting test scores and decibel meter recordings.

PRIMARY OUTCOME MEASURES

Prevalence of micrographia in the PD cohort and the clinical factors that correlate with micrographia.

RESULTS

68 subjects with PD were enrolled (68 men; mean age 72.3 years). Micrographia was identified in 63.2% of the cohort on verbal history and in 50% of the cohort when the handwriting test was used for ascertainment. Micrographia ascertained on history correlated significantly with disease severity (Hoehn & Yahr stage), motor impairment (Unified Parkinson's Disease Rating Scale), cognitive impairment (MMSE) and both bradykinesia and hypophonia determined by history and quantitative testing. Micrographia on handwriting test correlated with age (p=0.02), MMSE testing (p=0.04), hypophonia by history (p=0.01) and bradykinesia by quantitative testing (p=0.04).

CONCLUSION

Micrographia was found in nearly half of the PD cohort. Disease severity and impaired cognition were important clinical correlates. Micrographia had a significant relationship with bradykinesia and hypophonia, suggesting a possible overlap in their pathophysiology.

On the genesis of unilateral micrographia of the progressive type

We report a patient who, following a focal ischemic lesion of the left basal ganglia, developed right hand micrographia characterised by progressive reduction of letter size during writing (progressive micrographia). The patient did not show relevant cognitive impairments, but achieved pathological scores in tests for verbal fluency, and cognitive flexibility and monitoring. A systematic investigation of the writing performances demonstrated that micrographia showed a clear length effect in whatever writing style or task, while it was not observed in drawing, or in left hand writing to a comparable extent. Right hand progressive micrographia was not affected by a concurrent motor and cognitive load; instead, switching between two kinds of allographic responses and presenting one letter at a time in copying tasks reduced severity of micrographia significantly. These findings support the view that progressive micrographia in our patient could be ascribed to a defect in regulating the motor output on the basis of self-generated strategies. This conclusion would be consistent with neuroimaging evidence about the role of the basal ganglia in the control of motor sequencing, and could suggest that progressive micrographia might be associated with specific executive defects.

Post graphemic impairments of writing: the case of micrographia

Micrographia (MG), an acquired impairment of writing characterized by diminution of letter size, coupled with slowing and loss of accuracy, is most frequently observed in the course of degenerative disease of basal ganglia, such as Parkinson's Disease. Only a few cases of MG without concomitant extrapyramidal signs have been described, mostly following vascular lesion of the left basal ganglia. In this article we report an isolated pattern of MG following an extensive traumatic cerebral lesion centered in the left basal ganglia. The nature of this impairment is analyzed according to a cognitive model of writing and interpreted as a specific example of peripheral dysgraphia.