Subramanian Senthilkumaran1, Chidambaram Ananth2, Ritesh G Menezes3, Ponniah Thirumalaikolundusubramanian4. 1. Department of Emergency and Critical Care Medicine, Erode Emergency Care Hospital, Erode, Tamil Nadu, India E-mail: maniansenthil@yahoo.co.in. 2. Department of Anesthesiology, Chennai Medical College and Research Centre, Irungalur, Trichy, Tamil Nadu, India. 3. Forensic Medicine Division, Department of Pathology, College of Medicine, King Fahd Hospital of the University, University of Dammam, Dammam, Saudi Arabia. 4. Department of Internal Medicine, Chennai Medical College and Research Centre, Irungalur, Trichy, Tamil Nadu, India.
Sir,The informative case report by Dayal et al.[1] has reinforced the need to search and look for bedside clinical clues to diagnose the underlying complications and/or status in snake bite. The patient cited[1] had both internal and external ophthalmoplegia, which mimicked brain death in many ways, and prompted the intensivist to withdraw ventilator support, with potential catastrophe. With regard to the case reported, we would like to add on to the clinical, diagnostic, therapeutic and behavioural aspects based on our earlier experiences.[2] In locked-in syndrome (LIS), the patient will exhibit features of quadriparesis and anarthria with preservation of consciousness, and retention of vertical eye movements, provided the patient is not in circulatory failure. The patients with LIS express non-verbal communication through vertical eye movements. In addition, frontalis muscle tends to escape even in severe cases of LIS.[3]The progression of the case[1] to the comatose state cannot be attributed simply to cerebral hypoxaemia, as the patient was well oxygenated. The deep and reversible coma is likely be due to the effects of the venom on the cortical and brain stem structures[4] and probably at synapses. Irreversible binding of venom to pre-synaptic portion makes clinical recovery slow in krait envenomation, as recovery occurs only with the formation of new neuromuscular junctions. In such cases, somatosensory evoked potential response with median nerve stimulation helps not only to diagnose the condition/status, but also to differentiate LIS from other neurological conditions.As the patients with LIS are invariably conscious and observe what is happening in and around, and hear the conversations, physicians and nurses handling such cases should be cautious of their words, deeds and communications so as to avoid conflicts between care providers and the beneficiary. In neurotoxic snake envenomation, paralysis by and large begins with proximal muscles first and then progresses to distal muscles invariably, whereas recovery occurs in the reverse order. Moreover, these cases require supportive measures till the effects of venom wear off, and a thorough assessment is made before embarking on next management options.