Acute Hemiballismus: Clinical Picture and Etiology
Motor disorders can develop lightning-fast. A typical clinical example is the development of hemiballismus in a 63-year-old man against the background of vascular risk factors (resistant arterial hypertension, type 2 diabetes mellitus, obesity).
Main manifestations:
- Acute, sudden onset.
- Sudden, uncontrolled choreiform movements in the left limbs (arm and leg), resembling throwing or wing-flapping movements.
- Loss of ability to hold objects in the affected left hand (dropping objects).
- Inability to stand and walk independently due to marked restlessness and excessive movements.
The cause of this condition in this case was a lacunar (microangiopathic) infarction. The lesion was localized in the right subthalamic nucleus. Timely initiated symptomatic treatment with antipsychotics led to the complete regression of all motor disorders within a few days.
Neuroimaging in Vascular Hemiballismus
To confirm the diagnosis of acute infarction, the correct choice of magnetic resonance imaging (MRI) mode is critical:
- Diffusion-Weighted Imaging (DWI): Serves as the gold standard for detecting acute ischemia. Clearly visualizes the area of fresh damage in the subthalamic nucleus.
- T2-Weighted Imaging (T2-WI): Shows a hyperintense lesion in the same area, but does not allow such reliable differentiation of a fresh infarction specifically.
When analyzing MRI scans of the basal ganglia, differential diagnosis must be performed. In particular, hyperintense lesions may turn out to be enlarged perivascular spaces (Virchow-Robin spaces) rather than ischemic zones. Also, elderly patients with a similar history often show concomitant marked cerebral atrophy.
Wilson's Disease: Features of Movement Disorders
Unlike vascular catastrophes, hereditary metabolic disorders progress slowly. A typical profile is a 17-year-old young man suffering from progressive clumsiness in his hands for three years.
Anamnesis and Physical Status:
- Motor function: Loss of ability to write in cursive (switching to print), significant deterioration of fine motor skills in both hands and feet. The gait is slightly clumsy, and jumping on one leg is difficult.
- Tremor and tone: Fine high-frequency intention tremor of the hands (aggravated when trying to grab an object, present for about a year, predominating on the right). Bradykinesia and dysdiadochokinesia are observed (more pronounced on the left).
- Cranial nerves and face: Marked hypomimia (with normal tone and trophism of the facial muscles), mild saccadic eye movements during smooth pursuit. Speech is slowed, with errors.
- Coordination: Positive tandem gait test with eyes closed (falling in all directions), but the finger-to-nose test is performed flawlessly by the patient.
- Sensation and reflexes: No pathology (tendon reflexes are brisk and symmetrical, no pyramidal signs).
Diagnostics of Wilson's Disease: MRI and Laboratory
Making a diagnosis requires a comprehensive approach, including an ophthalmological examination, laboratory tests, and neuroimaging.
Key markers:
- Ophthalmology: Slit-lamp examination of the cornea reveals the specific Kayser-Fleischer ring.
- Laboratory findings: Significant increase in urinary copper excretion against the background of a low serum ceruloplasmin concentration.
MRI findings (T2-weighted images): Symmetric signal changes in brain structures directly associated with the toxic effects of copper:
- High signal intensity: in the putamen (putamen, especially in the lateral part), caudate nucleus (nucleus caudatus), lateral thalamus, midbrain (especially around the nucleus ruber), and middle cerebellar peduncles. This reflects toxic parenchymal changes due to high blood copper concentration.
- Low signal intensity: in the globus pallidus (globus pallidus) bilaterally, due to direct local copper deposition in this zone.
Briefly: answers to topical questions
What is myoclonus and what are the main types of myoclonus classified according to the level of the nervous system lesion?
Myoclonus is a sudden, brief, shock-like jerk of individual limb segments. Depending on the level of generation (localization of the nervous system lesion), the following types of myoclonus are distinguished:
- Cortical — generated in the somatosensory cortex of the cerebral hemispheres.
- Subcortical — generated in the basal ganglia.
- Brainstem — generated in the brainstem.
- Spinal — generated in the spinal cord.
Additionally, by pathogenesis, myoclonus is divided into positive and negative, and by distribution — into focal, segmental, and generalized.
Which pharmacological agents are used for the symptomatic treatment of myoclonus?
Antiepileptic drugs are used to treat myoclonic epilepsy:
- Clonazepam — a benzodiazepine derivative; used for myoclonic epilepsy.
- Valproic acid — the drug of choice for myoclonic epilepsy.
- Carbamazepine — the drug of choice for myoclonic epilepsy.
How does myoclonus clinically differ from chorea and ballism?
Myoclonus clinically differs from chorea and ballism in the character of movements:
| Sign | Myoclonus | Chorea | Ballism |
|---|---|---|---|
| Nature of movements | Sudden, brief, shock-like jerking of individual limb segments | Smooth hyperkinesias | Wide-amplitude, large-scale, flinging movements |
| Amplitude | Not specified in sources | Not specified in sources | Wide-amplitude, large-scale |
| Localization | Individual limb segments | Not specified in sources | Predominantly proximal limb joints |
Class and exam questions
What is the difference in detecting acute infarction on MRI using DWI versus T2 sequences?
DWI (diffusion-weighted imaging) clearly and unambiguously visualizes fresh ischemic lesion zones, whereas T2-WI shows a hyperintense focus but does not allow such reliable confirmation of its acuity.
What mimics lacunar infarctions in the basal ganglia on MRI?
Hyperintense areas may turn out to be enlarged perivascular spaces (Virchow-Robin spaces) rather than true zones of infarction.
Why does the MRI signal intensity in the globus pallidus change in Wilson's disease?
The decrease in signal intensity on T2-WI in the globus pallidus is due to local copper deposition in this structure.
What else to study on this topic
- Mechanism of action of neuroleptics in subduing hemiballismus.
- Pathophysiology of Virchow–Robin space formation.
- Neurological mechanisms of dysdiadochokinesia and intention tremor.
- Role of ceruloplasmin in human copper metabolism.
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