Complete resolution of myoclonus-like involuntary movements under subarachnoid block after midazolam administration in a patient undergoing cesarean section: a case report

New-onset movement disorder in the immediate postpartum period

This case report describes a woman who developed involuntary, uncoordinated movements of her face and limbs following a spontaneous vaginal delivery, complicated by postpartum haemorrhage. Using systematic assessment with multidisciplinary team input, a differential diagnosis was proposed and relevant investigations were undertaken. Atypical eclamptic or generalised seizures were excluded clinically and neuroimaging ruled out an intracranial vascular event such as stroke or venous sinus thrombosis. Local anaesthetic systemic toxicity was managed empirically with intravenous lipid emulsion and intravenous fluids. A diagnosis of drug-induced dyskinesia was made, most likely secondary to ondansetron, with which dystonias and myoclonus have been described. This woman's symptoms were transient and resolved within 2 hours.This case presented a complex differential diagnosis, highlighting the paucity of guidance available. We propose a diagnostic algorithm to aid in the identification of acute involuntary movements in pregnancy and the puerperium.

Transient involuntary movement disorder after spinal anesthesia: A case report

BACKGROUND

Spinal anesthesia is commonly used for various surgeries. While many complications occur after induction of spinal anesthesia, involuntary movement is an extremely rare complication.

CASE SUMMARY

Herein, we report the case of a 54-year-old healthy male patient who experienced involuntary movements after intrathecal injection of local anesthetics. This patient had undergone metal implant removal surgery in both the lower extremities; 7 h after intrathecal hyperbaric bupivacaine administration, involuntary raising of the left leg began to occur every 2 min. When the movement disorder appeared, the patient was conscious and cooperative. No other specific symptoms were noted in the physical examination conducted immediately after the involuntary leg raising started; moreover, the patient's motor and sensory assessments were normal. The symptom gradually subsided. Twelve hours after the symptom first occurred, its frequency decreased to approximately once every three hours. Two days postoperatively, the symptoms had completely disappeared without intervention.

CONCLUSION

Anesthesiologists should be aware that movement disorders can occur after spinal anesthesia and be able to identify the cause, such as electrolyte imbalance or epilepsy, since immediate action may be required for treatment. Furthermore, it is crucial to know that involuntary movement that develop following spinal anesthesia is mostly self-limiting and may not require additional costly examinations.

Spinal myoclonus following neuraxial anesthesia: a literature review

Spinal myoclonus (SM) is a rare neurologic movement disorder following neuraxial anesthesia (NA). SM following NA (SM-NA) has insufficient clinical information and its pathogenesis remains to be elucidated. The aim of this review article was to summarize the past cases and consider SM-NA pathophysiology. Based on our PubMed search, it was revealed that SM-NA develops within several hours after neuraxial local anesthetic (LA) administration and resolves in a day without leaving neurologic compilations. It occurs primarily in the lower extremities, but can sometimes spread upward and affect the upper extremities and trunk. Although statistical adjustments are indispensable, analysis of the previous cases provided important facts that seem to be related with the mechanism of SM-NA. The frequently used LAs for spinal anesthesia were hyperbaric. SM-NA occurrence was more frequent in women. After initiation of spinal anesthesia, intrathecal hyperbaric LA distributes cephalad. In the LA elimination process, the large concentration differences in intrathecal LA may induce the partially functioning spinal neurons, resulting in myoclonus generation. The morphological features of the lumbar spine in women can predispose to a higher LA concentration difference. SM-NA is an unpredictable and rare neural complication following NA and should be confirmed by basic experiments and large-scale researches.