1. Fever with altered sensorium Shilanjan Roy Dept Of Medicine Burdwan Medical College

2. Introduction A patient with fever and altered sensorium constitutes a medical emergency. Early recognition, efficient decision making and rapid institution of therapy can be life saving. 3. Levels of consciousness: Alert: Fully conscious Lethargic: Appear somnolent, but may be able to maintain arousal.Obtunded: Requires touch or voice to maintain arousal. Stuporous: Unresponsiveness from which the individual can be aroused only by painful stimulus. Comatose: State in which patient is unable to arouse or respond to noxious stimuli and is completely unaware of self and surroundings. 4. Fever with altered sensorium-- causes A. INFECTIONS Encephalitis Meningitis Cerebral malaria Brain abscess, subdural or epidural empyema Sepsis associated encephalopathy(SAE) Sepsis with DIC/TTP 5. Causes contd.. B. NON INFECTIOUS CAUSES OF FEVER a. OVERPRODUCTION OF HEAT : 1. Neuroleptic malignant syndrome 2. Malignant Hyperthermia. 3.Serotonin Syndrome 4.Cocaine, Amphetamine, ecstasy toxicity 5.Salicylate poisoning. 6.Thyrotoxic encephalopathy. 7.Convulsive status epilepticus. 8.Catatonic schizophrenia 6. b. IMPAIRED HEAT DISSIPATION 1.Anticholinergic toxicity e.g amitriptyline 2.Heat Stroke. c. STRUCTURAL LESIONS( IMPAIRED THERMOREGULATORY MECHANISM) 1.Hypothalamic lesion. 2.Brainstem lesion( stroke) 3.Intraventricular and subarachnoid haemorrhageICH with Intraventricular extensiond. MISCL. 1. ADEM(infectious or post infectious) 2.cerebral fat embolism 3.Altered sensorium with secondary cause of fever eg. Aspiration pneumonia in a stroke patient. 7. Important points: Presence of fever alone is not sufficient to make a diagnosis of an infectious etiology( e.g Meningitis or encephalitis) Encephalopathy may be precipitated by systemic infections or sepsis without cerebral inflammation (septic encephalopathy) Sepsis can lead to altered sensorium secondary to metabolic alterations like hypoglycaemia , hyperpyrexia, hypovolemia, hepatic or renal failure. Even in absence of infection there can be high rise of temp due to mechanisms such as overproduction or impaired dissipation of heat, non infectious CNS diseases, hypothalamic lesion. 8. Patients of NMS may have fever, neck stiffness, delirium, generalised rigidity, even after the offending drug has been withdrawn.WORLDWIDE , infection of the CNS is the commonest cause of Fever with altered sensorium. In a study from India among children < 18 yrs of age, commonest cause of acute febrile encephalopathy was VIRAL MENINGITIS, accounting for 40% of the cases. Among non viral, bacterial ( 34%), tubercular meningitis (7.9%) and cerebral malaria (5.2%) were most common. 9. Causes of infectious meningoencephalitis: A. VIRAL: a. DNA virus: 1. Herpes viruses: herpes simplex (HSV1,HSV2) other herpes viruses (HHV6, EBV, VZV, CMV) 2. Adenovirus. b. RNA viruses: Influenza, Polio, Entero, Measles, Rubella, Mumps, Rabies, Arbo, Reo, & Retrovirus 10. B. BACTERIAL: 1. Pyogenic meningitis 2. Mycobacterium tuberculosis 3. Mycoplasma pneumoniae 4. Listeria monocytogenes 5. Borrelia burgdorferri. 6. Tropheryma whippeli 7. Leptospira, 8. Brucella, 9. Legionella 10. Salmonella typhi. 11. C. RICKETTSIAL: Rickettsia rickettsii, R. typhi, R. prowazekii Coxiella burnetti D. FUNGAL: Cryptococcosis, coccidiomycosis, histoplasmosis, blastom ycosis, candidiasis E. PARASITIC: Plasmodium, trypanosoma, Toxoplasma, Naegleria, schist osoma 12. APPROACH TO THE PATIENT HISTORY: Most important Sometimes only clue to correct diagnosis. Careful and systematic clinical assessment is key to management of a patient of febrile encephalopathy. Imp to differentiate infective vs non infective causes. Temporal course is also imp whether fever preceded or followed altered sensorium or simultaneous. Classical triad of CNS inf fever, neck rigidity, altered mental status. (present in majority of patients) 13. HISTORY: imp points: Onset of altered sensorium Headache Fever grade/type Joint pain /rashes Nausea/vomitting Contact with animals/dog bite Seizures imp in children Focal deficits Geographical area Recent travel Drug addiction/use of antipsychotics Treatment with immunosuppressants/chemotherapy Trauma Recent illness/surgery Comorbidity such as diabetes 14. Physical examination: Thorough physical examination & neurological examination can provide imp clues to underlying aetiology. Skin rashes are common in meningococcal infn, rickettsial fever, VZV, colorado tick fever Parotitis in mumps Erythema nodosum may be a/w TB & histoplasmosis mucous membrane lesions common in Herpes virus infn, Upper resp tract infn favour Influenzae or Mycoplasma Look for lymphadenopathy, hepatosplenomegaly. 15. Detailed neurological examination including Pupillary size(anisocoria) & reaction(loss) Forced eye deviation, Cranial nerve involvement, Decerebrate rigidity, Papilloedema Focal neuro deficit, Fundus examination for papilloedema help in diagnosis & planning investigations. Common focal abnormalities are Hemiparesis, Aphasia, Ataxia, Pyramidal Signs, Cranial Nerve Deficits, Involuntary Movements (Myoclonus & Tremors), Partial Seizures & Papilloedema. warrant neuroimaging prior to LPBabinski sign 16. Signs of suspected meningitis: Kernig sign: flexing hip & extending knee elicit pain in back n legs. Brudzinski sign: passive flexion of neck elicits flexion of hip Nuchal rigidity: severe neck stiffness. Jolt accentuation: exacerbation of existing headache with rapid head rotation 17. After getting clues from History and examination, investigations are tailored as per provisional diagnosis. 18. Investigations: BLOOD INVESTIGATIONS: TC, DC - CBC Coagulation profile Blood culture: +ve in 30-80% cases of bacterial meningitis. Serum CRP & Procalcitonin Blood biochemistry Arterial blood gases PBS: Relative lymphocytosis in viral meningitis. Leucopenia & thrombocytopenia in rickettsial infn & viral haemorrhagic fevers. For definitive diagnosis of malarial infnP. falciparum gamet 19. CXR: May reveal changes suggestive of infn such as Mycoplasma, Legionella, Tuberculosis LP: Always indicated when meningitis or meningoencephalitis is suspected. Includes: CSF pressure Gross examination for turbidity, cob web coagulum Colour Chemical examination: sugar, protein Cell count & cell types Microbiological examination: gram stain, india ink preparation, cultures PCR for tuberculosis, viral infn Latex agglutination Limulus lysate assay 20. CSF findingsNormalViralBacterialtubercularFungalOpening pressure60-180 mm of H2ONormalelevatedElevated/ variableElevated/ variableColourClearUsually clearTurbid/xant hochromicXanthochro Clear/ mic/variable variableTC