Todd’s paralysis

Todd’s paralysis also called Todd’s paresis is a transient focal weakness of the hand, arm or leg which follows partial seizure activity within that limb ¹. Todd’s paralysis was first described by Robert Bentley Todd in 1849 ². The weakness can range in severity from mild to complete paralysis and usually occurs on just one side of the body. Todd’s paralysis can last from minutes to hours. Todd’s paralysis after a seizure is usually resolved in one or two hours but may, on occasion, continue for several days with with an average of 15 hours. It may occur in up to 13% of seizure cases. Todd’s paralysis may affect speech, eye gaze or vision. It most commonly occurs after generalized tonic clonic seizures. According to the literature knowledge, about 6% of patients who had tonic clonic seizures experienced Todd’s paralysis ³.

It is important to distinguish Todd’s paralysis from a stroke, which it can resemble, because a stroke requires completely different treatment.

Treatment of Todd’s paralysis is symptomatic and supportive because it resolves quickly.

Todd’s paralysis duration

The duration of Todd’s paralysis is generally considered to be short which can persist from half an hour to 36 hours, with an average duration of 15 hours, at which point it resolves completely and never persisted far beyond ⁴, whereas a longer duration was reported in stroke patients with a structural lesion in the seizure-generating hemisphere ⁵.

Todd’s paralysis causes

The exact underlying pathophysiology of Todd’s paralysis is still not well understood. Scientists don’t know what causes Todd’s paralysis. Current theories propose biological processes in the brain that involve a slow down in either the energy output of neurons or in the motor centers of the brain. According to a literature review ⁶, the possible mechanisms reported for the pathophysiology of Todd’s paralysis include neuronal exhaustion from hypoxia or energy and/or substrate depletion due to a possible damage or seizure activity in a localized brain region or an underlying vascular disease leading to insufficient metabolic processes ⁷. Moreover, inhibitory neuronal discharges as a result of endogenous inhibitory (possibly opioid) substances release may also be responsible for the existence of Todd’s paralysis ⁸.

Most case reports of reversible MRI findings cite increase in T2-weighted signals, increased regional cerebral blood volume, decreased apparent diffusion coefficient mapping, coupled with hyperperfusion in the postictal state ⁹. Hassan et al. ¹⁰ reported two cases of postictal paresis associated with computed tomography perfusion evidence of increased cerebral blood flow and volume and decreased mean transient time in the vascular territory corresponding to patient’s symptoms. These changes are believed to be in response to hypermetabolic neuronal activity from seizure discharges and can be differentiated from ischemia by the finding of increased perfusion ¹¹. Hypoperfusion has rarely been reported and when seen has occurred later in the postictal phase and after an initial period of hyperperfusion ¹².

Mathews et al. ¹³ described a similar case of an adult patient who presented with aphasia and right-sided hemiparesis with abnormal computed tomography perfusion studies, revealing a dramatic reduction in regional cerebral blood flow and regional cerebral blood volume but relative symmetry of mean transient time. A follow-up magnetic resonance perfusion study revealed normalization of cerebral blood flow. Leonhardt et al. ¹² assessed regional, dynamic, interictal, and postictal magnetic resonance perfusion changes in patients with temporal lobe epilepsy and documented relative hyperperfusion in the interictal period followed by hypoperfusion postictally. The study, however, did not assess changes in the mean transient time.

Todd’s paralysis symptoms

Todd’s paralysis also called Todd’s paresis is a transient focal weakness of the hand, arm or leg which follows partial seizure activity within that limb ¹. The weakness can range in severity from mild to complete paralysis and usually occurs on just one side of the body. Todd’s paralysis can last from minutes to hours. Todd’s paralysis after a seizure is usually resolved in one or two hours but may, on occasion, continue for several days. It may occur in up to 13% of seizure cases. Todd’s paralysis may affect speech, eye gaze or vision. Todd’s paralysis most commonly occurs after generalized tonic clonic seizures.

Todd’s paralysis treatment

There is no treatment for Todd’s paralysis. Individuals must rest as comfortably as possible until the paralysis disappears ¹⁴. Todd’s paralysis after a seizure is usually resolved in one or two hours but may, on occasion, continue for several days.

Todd’s paralysis prognosis

Todd’s paralysis is an indication that an individual has had an epileptic seizure. The outcome depends on the effects of the seizure and the subsequent treatment of the epilepsy ¹⁴.

References

1. Singh J. NON-EPILEPTIC ATTACK DISORDER AND TODD’S PARESIS: A CASE SERIES AND LITERATURE REVIEW. Journal of Neurology, Neurosurgery & Psychiatry 2012;83:A4 http://dx.doi.org/10.1136/jnnp-2012-304200a.17
2. Todd RB. On the pathology and treatment of convulsive disease. London Med Gazette. 1849;8:661–671. 724–729, 766–772, 815–822, 837–846.
3. Fisher RS, Schachter SC (2000) The postictal state: A neglected entity in the management of epilepsy. Epilepsy & Behavior 1: 52–59.
4. Rolak LA, Rutecki P, Ashizawa T, Harati Y (1992) Clinical features of Todd’s post-epileptic paralysis. Journal of Neurology, Neurosurgery, and Psychiatry 55:63-64.
5. Widdess WP, Devinsky O (2010) Historical perspectives and definitions of the postictal state. Epilepsy & Behavior 19: 96–99.
6. Prolonged Todd Paralysis: A Rare Case of Postictal Motor Phenomenon. Journal of Neurology and Neuroscience 2016; vol 7, No. 3; 103 https://www.jneuro.com/neurology-neuroscience/prolonged-todd-paralysis-a-rare-case-of-postictal-motor-phenomenon.pdf
7. Meyer JS, Portnoy HD (1959) Post-epileptic paralysis. A clinical and experimental study. Brain 82: 162-185.
8. Helmchen C, Steinhoff BJ, Dichgans M (1994) Variants of Todd’s paralysis: postictal apraxia and prolonged postictal hemineglect. Nervenarzt 65: 700-703.
9. Yacoub HA, Fenstermacher N, Castaldo J. Postictal Todd’s Paralysis Associated with Focal Cerebral Hypoperfusion on Magnetic Resonance Perfusion Studies. J Vasc Interv Neurol. 2015;8(2):32–34. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445347
10. Hassan AE, Cu SR, Rodriquez GJ, Qureshi AI. Regional cerebral hyperperfusion associated with postictal paresis. J Vasc Interv Neurol. 2012;5:40–42.
11. Cartagena A, Young G, Lee d, Mirsattari S. Neurology. 2012;78(Meeting Abstracts 1):P03–116. doi: 10.1212/WNL.78.1_MeetingAbstracts.P03.116
12. Leonhardt, G., De Greiff, A., Weber, J., Ludwig, T., Wiedemayer, H., Forsting, M. and Hufnagel, A. (2005), Brain Perfusion Following Single Seizures. Epilepsia, 46: 1943-1949. doi:10.1111/j.1528-1167.2005.00336.x
13. Mathews MS, Smith WS, Wintermark M, Dillon W, Binder D. Local cortical hypoperfusion imaged with CT perfusion during postictal Todd’s paresis. Neuroradiol. 2008;50:397–401.
14. Todd’s Paralysis Information Page. https://www.ninds.nih.gov/disorders/all-disorders/todds-paralysis-information-page