Prachaya Srivanitchapoom

Levodopa-induced dyskinesia: Clinical features, pathophysiology, and medical management

Levodopa-induced dyskinesia (LID) is commonly seen in Parkinsons disease patients treated with levodopa. This side effect is usually encountered after long duration of treatment, but occasionally, this may be seen even after few days or months of treatment. LID is broadly classified as peak-dose dyskinesia, wearing-off or off-period dyskinesia, and diphasic dyskinesia. Pathogenesis of LID is complex, and different neurotransmitters such as dopamine, glutamine, adenosine, and gamma-aminobutyric acid play important role altering the normal physiology of direct and indirect pathway of cortico-basal ganglia-thalamic loop responsible for fine motor control. Treatment of LID requires careful history taking and clinical examination to find the type of dyskinesia as different approach is required for different types. Changes in dopaminergic medication including continuous dopaminergic stimulation are very helpful in the management of peak-dose dyskinesia. Different types of surgical approaches including unilateral pallidotomy and deep brain stimulation have given very good result in patients, who cannot be managed by medications alone. The surgical management of LID is dealt with in detail in another review in this series.

Parkinsonian syndromes: A review

Since James Parkinson published his remarkable clinical observations in the “An Essay On The Shaking Palsy” in 1817, the number of diseases included in the spectrum of parkinsonian syndromes (a group of diseases that have some part of their clinical features resembling those seen in Parkinsons disease), are growing. Careful history taking, comprehensive neurological examination, and utilization of proper investigations will lead the physicians to make an accurate diagnosis of the specific disease entity present. In this recent review, we cover the issue of classification of parkinsonian syndromes, and comprehensively review the characteristic features of the commonly encountered diseases that present with this syndrome. The salient aspects of the epidemiology, key clinical features, proper investigations, and possible treatment options of these diseases have also been addressed.

Brainstem dysfunction heralding disseminated cryptococcosis

Cryptococcal meningoencephalitis is one of the most common central nervous system infections affecting immunocompromised patients. However, brainstem involvement is extremely rare and may represent a diagnostic challenge to clinicians. We report a non-HIV infected, chronically immunosuppressed, patient with fatal disseminated cryptococcosis presented with subcutaneous masses at both thighs and progressive brainstem dysfunction. Magnetic resonance imaging demonstrated multiple brainstem infarcts likely derived from small vessel vasculopathy. Anti-fungal treatment led to partial neurologic improvement but the patient succumbed to a fatal sepsis from hospital-acquired pneumonia.

Acute Dystonic Reaction Following General Anesthetic Agent Use

Background A 36-year-old Thai female who underwent a thymectomy under general anesthesia developed acute abnormal movements in the craniofacial region immediately after awakening with preserved consciousness. Phenomenology Intermittent abnormal movements included oculogyric crisis; tongue protrusion; blepharospasm; and oro-mandibular dystonia consisting of risus sardonicus, jaw opening, and right torticollis. Educational value An acute dystonic reaction can be a complication of either single or combined general anesthetic agents.

A Case of Functional Belly Dancer's Dyskinesia

A 51-year-old right-handed woman presented with abnormal abdominal movements for 9 years. She was in good health until she suddenly felt extreme pain in the middle of her back and the right leg during Pilates class. A few days later, she developed constipation, bloating, and severe pain in abdominal muscles. In 3 months, she started noticing slow writhing and undulating belly movements. Her movements were continuous during the day, but it was not clear whether it persisted during sleep. She started seeking medical attention and was found to have left ninth rib fracture. She underwent a rib repair surgery. She also received fundoplasty for acid reflux, which did not abate the symptoms. Because of chronic pain, she had CT-guided T8/T9 nerve root block followed by intercostal nerve block at T8/9 and T12 level, which resulted in pneumothorax without benefit. Her movements became more intense and disabling along the course. Six years after the onset of her symptoms, she was diagnosed with BDD by a movement disorder specialist. She was started on clonazepam, baclofen, and gabapentin as well as botulinum neurotoxin injection in bilateral rectus abdominus, abdominal external oblique (AEO), and left thoracic paraspinal muscles, which was slightly helpful. Neurological exam showed slow abdominal contraction that caused either undulating or circular umbilical movements (see Video 1). She could stop the movement by holding her breath when suggested to do so. The movements were neither distractible nor entrainable to hand tapping and alternating hand movement. MRI of her brain and spine were normal. Surface electromyography (EMG) showed irregular EMG bursts with variable duration of 1,000 to 3,000 ms and cocontraction in bilateral AEO. Frequency varied from 0.3 to 1 Hz (Fig. 1A). The movements completely disappeared with sleep on EEG-EMG recording (Fig. 1B). Jerk-locked back-averaging of EEG-EMG was performed by placing the marker at the onset of EMG activity of AEO and back-averaging EEG in central leads (Fz, Cz, F3, F4, C3, and C4) for 3,000 ms to +1,000 ms from the marker. A slowly rising negative potential was observed in central leads, starting around 1000 ms preceding movement onset consistent with a Bereitschaftspotential (BP) (Fig. 1C). The diagnosis of functional BDD was made based on presence of BP, in addition to clinical features of suggestibility and variability of the movement.

Teaching NeuroImages: Erdheim-Chester disease (polyostotic sclerosing histiocytosis).

A 34-year-old man presented with progressive visual loss, diplopia, headache, intermittent fever, and significant weight loss for 7 months. Physical examination revealed bilateral visual loss and exophthalmos with complete ophthalmoplegia. Imaging demonstrated pachymeningeal enhancement, soft tissue infiltration in the retro-orbital spaces and multiple organs including kidneys and abdominal aorta, and mixed osteosclerotic and osteolytic lesions in bilateral femoral heads1 (figure). Pathologic study of the retro-orbital lesion revealed foamy histiocytes negative for CD1a and S100,2 consistent with Erdheim-Chester disease (ECD). The patient was treated with IV methylprednisolone followed by cyclosporine with minimal benefit. Four months later, he died due to sudden unexplained death during sleep. An autopsy was not performed. ECD is a rare, non-Langerhans histiocytosis characterized by chronic histiocytic infiltration of multiple organs. Common manifestations include bone pain, diabetes insipidus, exophthalmos, and xanthelasma.1 The nervous system is affected in 25%–50% of patients and can be involved in the extra-axial and intra-axial compartments.1,2 Standard treatment has not been established.

Combined Encephalopathies in Severe Malnutrition and Liver AbscessTreated with Metronidazole

A 69-year-old woman presented with deterioration of level of consciousness and ataxia for 2 weeks. She was diagnosed pyogenic liver abscess 3 months ago and had developed severe malnutrition since then. Liver abscess was successfully treated with ceftriaxone and metronidazole 1 month ago. Drowsiness, horizontal nystagmus, cerebellar dysarthria and ataxia were observed. She was clinically diagnosed Wernicke’s encephalopathy (WE). Interestingly, her brain MRI showed a combination of typical finding [1] including mammillary bodies (Figure 1A and 1B; black arrow), and pontine tegmentum hyperintensities (Figure 1C; head arrow). Atypical findings of red nucleus (Figure 1A; white arrow), splenium (Figure 1B; head arrow), and dentate nucleus hyperintensities (Figure 1C; black arrow) of WE which were described in metronidazole-induced encephalopathy (MIE) [2]. Gradient echo sequence showed small bleeding in left dentate nucleus (Figure 1D; arrow). Combined WE with MIE were diagnosed. All neurological symptoms were disappeared after intravenous infusion of thiamine. Combined WE and MIE are a rare condition but they can concomitantly occur in the setting of severe malnutrition with history of taking metronidazole. In addition, bbleeding in dentate nucleus has never been described in literature. Reference