1. Yasaman Kianirad, MD

2. Case presentation HPI: o 65 y/o AA right-handed M o Acute onset while he was watching a football game on the TV o Involuntary, intermittent, insuppressible movement o Present both at rest and during activities, but not sure if it was present during sleep o No aggravating or alleviating factors o No LOC

3. PMHx: o HTN o HLD o Stage III chronic kidney injury o Hx of polysubstance abuse Home Medications: o HCTZ 25 mg daily o Lisinopril 40 mg po daily o Sildenafil 100 mg q weekly as needed o Simvastatin 20 mg qhs o Tramadol 100 mg q 6hours as needed

4. Family History: o No hx of movement disorders, seizures or other neurologic diseases Social History: o Denies smoking and EtOH, o quitted using cocaine 4 years ago

5. Neuro exam: o MS : A&O x 3 o CNs : PERRLA, EOMI, face symmetric, tongue midline o Motor : no atrophy, normal tones, 5/5 in strength o Moderate-amplitude, low-frequency (2-3 Hz), semirhythmic, involuntary movement of his right arm, mainly at his elbow in the extension-flexion manner present at rest, during activities, during sustained posture and FNF. o After half an hour, we checked on him again, and at this time the abnormal movement became more prominent at his right wrist instead of right elbow o Sensory : intact o Coordination : FNF showed no dysmetria, RAM intact o Gait : normal

7. Lab results Glucose 1,068 mg/dl MRI and MRA were unremarkable

8. Skeletal myorhythmia coarse, involuntary, relatively rhythmic, alternating tremor with frequency of 2 to 3 cycles per second Intermittent or continuous or both types present at rest, action, and with sustained posture. Suppressed during sleep can be present in single or multiple body parts If multiple areas are involved, the movement can be synchronous or asynchronous Accentuated or suppressed by a variety of factors including peripheral stimulation, emotional stress, and coughing

9. Elmo F Masucci, John F Kurtzke : Myorhythmia: A Widespread Movement Disorder; Clinicopathological Correlations. Brain (1984), 107, 53-79 24 cases of myorhythmia were studied The most common etiologies were brainstem vascular disease and cerebellar degeneration 2/2 chronic alcoholism-nutritional deficiency According to their autopsy (6/24), myorhythmia of the limbs may occur ipsilateral to the dentate nucleus or superior cerebellar peduncle lesions or contralateral to inferior olive involvement

10. Commonly involved body part o Head o Platysma o Facial muscle o Pharynx o Palate o tongue, o Larynx o Smaller muscle of the limbs

11. Myorhythmia Clinical Features No. Frequency (rate/min) o 60-1191 o 120-18022 o 181-2401 Occurrence o Continuous5 o Intermittent15 o Both4

12. No. Character o Simple flexion-extension11 o Rotary4 o Complex(flexion-extension plus adduction-abduction or supination-pronation) 9 Etiology o Brainstem infarct10 o Alcoholic cerebellar degen. 6 o MS 2 o Hereditary ataxia 2 o Viral encephalitis 1 o Phenytoin toxicity 1 o Collagen-vasc. Disease 1 o Undetermined 1

13. Other etiologies of isolated limb myorhythmia thalamic stroke limbic encephalitis hashimoto encephalopathy listerial rhombencephalitis paraneoplastic disorder

14. Types of abnormal movements associated with hyperglycemia MovementLevel of evidence o Hemichorea-hemiballism ++ and generalized chorea o Opsoclonus-myoclonus + o Holmes’ tremor + o Hemifacial spasm+/- o Paroxysmal kinesigenic dyskinesia +/- o Stereotypies+/- +/- single case report + few case reports ++ well-defined

15. Neuroimaging

16. “Diabetic striatopathy” or “diabetic striatal disease” MRI o T1W : hyperintensity of the contralateral putamen without surrounding edema o T2W : Hyper/hypo/isointensity of the contralateral putamen o DWI : increased signal in the putamen with hypo/hyperintensity on ADC CT o Normal or hyperdense

17. Pathophysiology Unclear mechanism Three proposed theories o Petiechial hemorrhage  hyperintense signal changes on T1W  GRE/ pathology in few patients o Hyperviscosity  high serum osmolarity->reduction in blood flow- >transient ischemia  SPECT and PET studies showed reduced blood flow and metabolism in the contralateral striatum o Depletion of GABA and acetylcholine neurotransmitters in the BG  Anaerobic pathways during hyperglycemia->brain uses GABA to create energy and Acetate production reduced

18. Pathology Variable pathological changes o Gliotic brain tissue with abundant reactive astrocytes o Petechial hemorrhage o Calcification o Multiple small hemorrhages Limited by the timing of autopsy and the presence of other coexisting conditions

19. Treatment Controlling blood glucose o Resolved in days -months Typical/atypical antipsychotics o Haloperidol, chlorpromazine, pimozide Dopamine depleting agents o Tetrabenazine, reserpine Benzodiazepines o Diazepam, clonazepam Anticonvulsants o VPA, topiramate