Objective: Metabolic encephalopathy is a common cause for morbidity and mortality in elderly. Metabolic disturbances are frequent causes of impaired consciousness and their presence must always be considered when there are no focal signs of cerebral disease. An underdiagnosed but potentially treatable cause of metabolic encephalopathy in elderly is Hashimoto’s encephalopathy (HE). It has huge clinical relevance since it is not uncommon and shows very good response to immunosuppressive treatment. The aim of the study was to analyse the various causes of metabolic encephalopathy in elderly patients. Various presenting features of encephalopathy particularly involuntary movements have also been studied. Cases of Hashimoto’s encephalopathy have been specifically sought for and looked into to characterise the specific clinical manifestations that can point towards its diagnosis.

Materials and Methods: Our study was a hospital based descriptive study conducted in elderly patients above the age of 60 years admitted with altered sensorium. Patients with documented sepsis, hepatic failure ,renal failure,  cerebrovascular accident, CNS infection and head injury were excluded from the study. A thorough clinical examination including detailed neurological examination was done. Blood was sent for investigations including serum electrolytes, hepatic, renal and throid function tests. Those patients who did not had any obvious cause for encephalopathy and not responding to treatment were further evaluated with anti TPO antibodies in CSF.

Results: Of the 132 patients enrolled in the study there were 55males (41.7%) and 77 females (58.3%). Seizures was seen in 15.9% and myoclonus in 3.8% patients. Study showed that 92.4% of patients had hyponatremia and 7.6% had normonatremia. The patients having blood glucose values above 500 mg% and below  50 mg% were 4.5%, and 7.6%. Thus our study showed 7.6% of patients had hypoglycaemic encephalopathy Thyroid status of the patients  showed that clinical hypothyroidism was seen in 3.8% and subclinical hypothyroidism in 15.4%. Majority of the patients were euthyroid(80.8%).The CSF examination showed 14 patients (10.6%) positive  for anti TPO antibodies and  were diagnosed to have hashimotos encephalopathy.Among the patients with hashimotos encephalopathy 71.4% were females , 57.2 % patients had abnormal movements  at presentation , 64.3 % patients had hyponatremia  and 78.5 %  had  a euthyroid status.

Conclusion:  Hyponatremia and altered blood glucose levels were the major causes leading to metabolic encephalopathy in elderly patients. About 10.6% of the elderly patients presented with hashimotos encephalopathy. Abnormal movements were an important presenting feature of hashimotos encephalopathy. A Significant proportion of patients with hashimotos encephalopathy had  euthroid status. A high level of clinical suspicion is needed for the diagnosis, as it is a treatable condition.

Keywords: Hasimotos encephalopathy, seizures, anti TPO antibodies, hyponatremia, euthyroid.

1. Hoorn EJ, Lindemans J, Zietse R: Development of severe hyponatraemia in hospitalized patients: treatment-related risk factors and inadequate management. Nephrol Dial Transplant 2006;21:70-76. Brain, L; Jellinek, E.G.; Ball, K. Lancet 1966, ii, 512.
2. Brain, L; Jellinek, E.G.; Ball, K. Lancet 1966, ii, 512.
3. Jesus Montenegro, MD, Olga Gonzalez, MD ; Changes in renal function inprimary hypothyroidism; American Journal of Kidney Diseases; Volume27, Issue 2 , Pages 195-198, February 1996.
4. M Seipelt, I Zerr, R Nau, B Mollenhauer, S Kropp, B J Steinhoff, R W C Janzen ; Hashimoto’s encephalitis as a differential diagnosis of Creutzfeldt- Jakob disease; J NeurolNeurosurg Psychiatry 1999;66:172-176
5. Riggs JE. Neurerlogical manifestations of electrolyte disturbances. Neurology Clinics 2002, 20:227-239
6. Michael L. Moritz and J. Carlos Ayus;The pathophysiology and treatment of hyponatraemic encephalopathy: an update ; Nephrol Dialysis Transplantation (2003) 18: 2486-2491
7. Rebecca M. Reynolds, Jonathan R. Seckl; Hyponatraemia for the clinical endocrinologist; Volume 63, Issue 4, pages 366-374, October2005
8. H. Schmitz, P. H. E. M. de Meijer and A. E. Meinders; Hyponatremia due to hypothyroidism: a pure renal mechanism’; The Netherlands Journal of Medicine; Volume 58, Issue 3, March 2001, Pages 143-145
9. Ji Y. Chong, MD; Lewis P. Rowland, MD; Robert D. Utiger, MD ;Hashimoto Encephalopathy: Syndromeor Myth? ArchNeurol. 2003;60:164-171.
10. Matsunaga A, Yoneda M. Anti-NAE autoantibodies and clinical spectrum in Hashimoto's encephalopathy. 2009 Mar;57(3):271-8.
11. Abhijit Chaudhuri and Peter O. Behan; The Clinical Spectrum, Diagnosis, Pathogenesis and Treatment of Hashimoto’s Encephalopathy (Recurrent Acute Disseminated Encephalomyelitis); Current Medicinal Chemistry,2003, 10, 1945-1953 1945.
12. Gayatri NA, Whitehouse WP; Pilot survey of Hashimoto's encephalopathy in children; Dev Med Child Neurol. 2005 Aug;47(8):556-8.
13. Sawka AM, Fatourechi V, Boeve BF, Mokri B; Rarity of Encephalopathy Associated with Autoimmune Thyroiditis: A Case Series from Mayo Clinicfrom 1950 to 1996; Thyroid. 2002 May;12(5):393-8
14. Mocellin, Ramon; Walterfang, Mark; Velakoulis, Dennis; Hashimoto's Encepha-lopathy: Epidemiology, Pathogenesis and Management. CNS Drugs, Volume 21, Number 10, 2007 , pp. 799-811(13)
15. Hemanta Kumar Nayak, Mrudul Kumar Daga, Unusual association of diseases/symptoms: A series report of autoimmune hypothyroidism associated with H^himoto's encephalopathy: an under diagnosed clinical entity with good prognosis ; BMJ 2010
16. Jesus Montenegro, MD, Olga Gonzalez, MD ; Changes in renal function inprimary hypothyroidism; American Journal of Kidney Diseases; Volume27, Issue 2 , Pages 195-198, February 1996.
17. Warner MH, Holding S, Kilpatrick ES: The effect of newly diagnosed hypothyroidism on serum sodium concentrations: a retrospective study. ClinEndocrinol (Oxf) 2006;64:598-599
18. GeorgiosKaranikas, Matthias Schutz, Monica Szabo, Alexander Becherer, Karoline Wiesner, Robert Dudczak, Kurt Kletter; Isotopic Renal Function Studies in Severe Hypothyroidism and after Thyroid Hormone Replacement Therapy; Am J Nephrol 2004 24:41-45
19. Riggs JE. Neurerlogical manifestations of electrolyte disturbances. Neurology Clinics 2002, 20:227-239.

Dr Praveen. P

Dept of Internal Medicine, Government Medical College,

Thiruvananthapuram-695011 Kerala, India

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