Dear Sir,

Injuries secondary to lightning strike are fortunately rare. Nervous system is commonly involved.[ 1 ] Cerebral hemorrhage following lightning injuries has been described and is, for unknown reasons, usually seen in the basal ganglia.[ 2 – 5 ] We report a case of young male presenting with basal ganglia bleed following lightning injury.

A 17-year-old male was struck by lightning while working in the field. He was found unconscious by his co-workers. He was hospitalized within an hour. Examination revealed left corneal ulceration (entry wound) and superficial burn injury over the right side of neck (exit wound). The electrocardiogram was normal. Neurologically, he was not responding to commands and was localizing to painful stimulus with the right upper limb. He had left hemiplegia. Computed tomography (CT) scan of head showed bleed with multiple layers in the right lentiform nucleus with mass effect [ Figure 1a ]. There was no coagulation abnormality detected. CT angiogram showed no abnormality in the neck and major intracranial vessels. There was no extravasation of dye. In view of the mass effect and poor neurological status, he underwent large decompressive craniectomy and evacuation of hematoma [ Figure 1b ]. He received intensive care and improved in sensorium. Gradually, the weakness improved.

Figure 1

(a) Pre-op Non-contrast computed tomography (NCCT) head showing right lentiform nucleus hematoma with mass effect following lightning strike. (b) Post-op NCCT head showing adequate decompression and evacuation of hematoma

Lightning injuries to central nervous system are second only to acute cardiovascular injuries as the principal cause of death. Neurologic complications after lightning consist of: 1) immediate and transient variety presenting with the symptomatology which includes loss of consciousness, amnesia, confusion, headache, paresthesia, and weakness; 2) immediate and prolonged or permanent variety which includes post-hypoxic-ischemic encephalopathy, intracranial hemorrhages, cerebral infarction and cerebellar syndromes; 3) delayed presentation after weeks to months including motor system disease and movement disorders and 4) destructive injuries secondary to falls.[ 1 ]

The mechanisms of neurological injuries include thermal effects, electrical effects, induced electrical currents, blast effects, and injuries related to falls. Lightning's electrical current is enormous, even though of brief duration, and causes immense thermal injury to tissues. Electric fields can damage the structural integrity of the lipid bilayer present in membrane of nerve and muscle tissues, termed as electroporation. The intense heating of the air surrounding the lightning flash can generate an explosive thunderous blast causing barotraumas.[ 1 ]

Intracranial hemorrhages in lightning-strike patients often appear in basal ganglia.[ 2 – 5 ] Blunt head trauma and acute hypertension secondary to intense peripheral vasoconstriction as a cause are unlikely as they rarely cause basal ganglia bleed.[ 2 ] Studies in sheep suggest that current may enter via orifices (eyes, nose, ears) and travel caudally from neocortex toward the basal ganglia and brainstem.[ 1 ] Blood vessels and neural tissue have been found to carry more current per unit area than the other tissues and to become damaged before the surrounding tissues, in an animal model. Preferential conduction along Virchow-Robin spaces in the anterior perforated substance has been a proposed mechanism of bleed after a lightning strike.[ 3 ] However, this mechanism does not explain the predilection for basal ganglia. Blood vessels in this region are almost perpendicular to the parent vessels and there is gross disparity in sizes. Thus, the current passing through these vessels would also be disproportionate and in opposite directions. The electromagnetic fields produced by the passing currents in these vessels exert forces in different directions, possibly leading to shearing of the smaller vessels from parent arteries.

Most victims of lightning who have not had a cardiac arrest will survive. Most of these patients are young, and with aggressive management, these patients survive to have a productive life.

References

1. Cherington M. Neurologic manifestations of lightning strikes. Neurology. 2003. 60: 182-5

2. Carrera-Izquierdo E, Morán-Sánchez JC, Carrera-Izquierdo M, Jiménez-Corral C, Rodríguez-Recio FJ, Ocastegui-Candial JL. Intracranial haemorrhage secondary to a lightning strike: A case report. Rev Neurol. 2004. 39: 530-2

3. Ozgun B, Castillo M. Basal ganglia hemorrhage related to lightning strike. AJNR Am J Neuroradiol. 1995. 16: 1370-1

4. Stanley LD, Suss RA. Intracerebral hematoma secondary to lightning stroke: Case report and review of the literature. Neurosurgery. 1985. 16: 686-8

5. Thomas M, Pillai M, Krishna Das KV. Intracranial haematoma resulting from lightning stroke. J Assoc Physicians India. 1991. 39: 421-2