EMERGENCY:Sudden worsening of confusion or coma in a patient with known liver disease —call040-46324365immediately — 24 hours, 7 days— 24/7
Hepatic Encephalopathy — Specialist Neurology and Hepatology Care in Hyderabad at KIMS
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome arising from liver failure or portosystemic shunting, in which neurotoxic substances that would normally be cleared by the liver accumulate in the systemic circulation and cross the blood-brain barrier. The principal neurotoxin is ammonia (NH₃), produced by gut bacteria from dietary protein and absorbed into the portal circulation. A healthy liver converts virtually all portal ammonia into urea via the urea cycle. When liver function fails — from cirrhosis, acute liver failure, or portosystemic shunting — ammonia bypasses the urea cycle and accumulates in the blood, reaching the brain where it disrupts astrocyte function, promotes cerebral oedema, impairs neurotransmission, and generates reactive oxygen species.
HE is a neuropsychiatric syndrome from liver failure or portosystemic shunting, in which neurotoxic substances normally cleared by the liver accumulate in the blood and cross the blood-brain barrier. It is a clinical diagnosis — neurological or psychiatric dysfunction in a patient with hepatic disease or portosystemic shunting, after other causes of encephalopathy have been excluded. Serum ammonia is a supportive marker used to guide and monitor treatment, not a diagnostic test: it can be normal in confirmed HE, and it rises in conditions unrelated to HE (GI bleeding, urinary infection, dietary protein, valproate). The principal toxin is ammonia (NH₃), produced by gut bacteria from dietary protein. A healthy liver converts portal ammonia into urea. When liver function fails, ammonia reaches the brain and is metabolised by astrocytes via glutamine synthetase → glutamine accumulates as an osmolyte → astrocyte swelling → in severe cases (acute liver failure) global cerebral oedema and intracranial hypertension. The ISHEN grading: Grade 1 (subtle cognitive change, sleep disturbance), Grade 2 (asterixis, disorientation), Grade 3 (confusion, somnolence), Grade 4 (coma). Minimal/covert HE (Grade 0): detected only by psychometric testing; present in 30–80% of cirrhotics; impairs driving (3–4× increased accident risk); highly responsive to lactulose and rifaximin. Precipitants follow the GEISMA framework: GI bleeding, Electrolyte abnormality, Infection, Surgery/procedure, Medications (sedatives, opioids, diuretics), Aspiration/constipation. India-specific: ATT-induced ALF (more common than paracetamol), ayurvedic/herbal hepatotoxicity, viral hepatitis B (3.5–4% prevalence) and C (1%).
- HE is a clinical diagnosis — ammonia alone is not diagnostic
- The diagnosis rests on neurological or psychiatric dysfunction in a patient with hepatic disease or portosystemic shunting, after excluding other causes — graded clinically by West Haven criteria. Ammonia is a supportive marker for monitoring treatment, not a confirmatory test: normal ammonia does not exclude HE, and elevated ammonia does not confirm it (GI bleeding, urinary infection, dietary protein, valproate, muscle breakdown and urea cycle disorders all raise it).
- Ammonia-astrocyte-glutamine mechanism
- Ammonia reaches the brain and is processed by astrocytes (the only brain cells with glutamine synthetase). Excess ammonia → excess glutamine synthesis → glutamine accumulates as an osmolyte inside astrocytes → osmotic water influx → astrocytes swell. In mild HE: diffuse astrocyte swelling impairs neurotransmission and causes the encephalopathy. In severe acute liver failure: the swelling is global, producing brain oedema and intracranial hypertension — the mechanism of brain herniation in fulminant hepatic failure.
- Asterixis — negative myoclonus (NOT a tremor)
- Asterixis (liver flap) is demonstrated by asking the patient to hold arms outstretched with wrists extended: the wrists show SUDDEN BRIEF LAPSES OF SUSTAINED POSTURE (the wrist suddenly drops and recovers, producing a flapping motion). This is negative myoclonus — a sudden brief LOSS of motor tone from transient suppression of cortical motor output. It is NOT a tremor (which is rhythmic oscillation of maintained tone). In the context of known liver disease, new asterixis = HE until proven otherwise.
- Minimal HE — the silent impairment
- Minimal/covert HE (Grade 0) is present in 30–80% of all cirrhotic patients — detected only by psychometric testing (NCT-A, Digit Symbol Test, computerised tests); not identifiable on standard bedside neurological examination. It significantly impairs driving safety (3–4× increased road accident risk) and work performance. At KIMS, psychometric testing for minimal HE is offered to all cirrhotic patients, with lactulose and/or rifaximin started when confirmed.
- GEISMA — find the precipitant first
- In most cirrhotic patients, the underlying liver disease alone does not tip into overt HE — a precipitating event does. The KIMS HE assessment protocol looks for: GI haemorrhage · Electrolyte abnormality (hyponatraemia, hypokalaemia, hypomagnesaemia) · Infection (SBP, UTI, pneumonia — diagnostic ascitic tap if ascites present) · Surgery/procedure · Medications (sedatives, opioids, diuretic overuse) · Aspiration/constipation. Treating the precipitant is the primary management step — lactulose and rifaximin are adjuncts.
- ATT ALF — India-specific emergency
- Anti-tuberculosis drugs (isoniazid + rifampicin + pyrazinamide) cause hepatotoxicity in 5–20% of patients; a small proportion develop fulminant hepatic failure. In India, ATT-induced ALF is proportionally more common than paracetamol-induced ALF (the dominant cause in Western countries). Any patient on ATT with jaundice + confusion = stop ATT immediately + assess liver function + assess King's College Criteria for liver transplant. Re-challenge with a modified regimen is done cautiously after recovery.
- Ayurvedic hepatotoxicity — the underreported cause
- A significant proportion of acute liver failure in India is caused by herbal, ayurvedic, siddha, unani, and homeopathic preparations containing pyrrolizidine alkaloids (from Heliotropium, Crotalaria plants) or Rasa shastra preparations with heavy metals. Patients do not volunteer this information when asked about "medications." A direct, non-judgmental inquiry — "Do you take any ayurvedic preparations, herbal remedies, or traditional medicines?" — is essential in every liver failure workup.
- Rifaximin RFHE trial — 58% HE reduction
- Rifaximin 550 mg twice daily reduces gut ammonia-producing bacteria with minimal systemic absorption (no significant drug interactions). The RFHE trial demonstrated a 58% reduction in the risk of recurrent HE episodes compared with placebo in patients with cirrhosis and prior HE. Used as add-on to lactulose for acute HE and as maintenance therapy for secondary HE prevention in any cirrhotic patient with two or more prior episodes.
| Fact | Details |
|---|---|
| Mechanism | Ammonia → astrocyte glutamine synthetase → glutamine osmolyte → astrocyte swelling → brain oedema (in ALF) · Also: neuroinflammation, impaired neurotransmission, BBB disruption |
| Diagnosis | Clinical diagnosis: neuropsychiatric dysfunction + hepatic disease or portosystemic shunting + exclusion of other causes · Ammonia is supportive only — normal ammonia does not exclude HE, elevated ammonia does not confirm it · Poor correlation with grade · Psychometric testing for minimal HE |
| ISHEN grades | 1: subtle cognitive + sleep · 2: asterixis + disorientation · 3: confusion + somnolence · 4: coma · Minimal/covert (Grade 0): psychometric testing only, 30–80% of cirrhotics |
| Asterixis | Negative myoclonus · Sudden brief LOSS of sustained posture · Wrists extended · NOT a tremor · Grade 2 HE marker |
| GEISMA precipitants | GI bleeding, Electrolytes (Na, K, Mg), Infection (SBP, UTI, pneumonia), Surgery, Medications (sedatives, opioids, diuretics), Aspiration/constipation · Treat precipitant first |
| ATT + ayurvedic ALF | ATT (HRZE): hepatotoxic 5–20%, more common cause of ALF in India than paracetamol · Stop ATT immediately if hepatotoxic · Ayurvedic: ask directly + non-judgmentally about all traditional preparations |
| Treatment | Lactulose 30–45 mL 2–3×/day (2–3 soft stools/day) + rifaximin 550 mg BD · Treat precipitant · LOLA adjunct · TIPS for refractory (but can worsen HE) · Liver transplant for ALF |
| Prevention | Rifaximin 550 mg BD: 58% reduction in recurrent HE (RFHE trial) · Continue indefinitely in cirrhotic patients with prior HE · Lactulose titrated to 2–3 soft stools/day (not watery diarrhoea) |
About This Condition
Hepatic Encephalopathy at a Glance
The essential facts that shape how hepatic encephalopathy is recognised and managed at KIMS — the ammonia / astrocyte-swelling mechanism, the ISHEN grading from minimal HE through Grade 4 coma, the GEISMA precipitants framework, the Indian chronic-liver context dominated by hepatitis B/C, alcohol and NAFLD, the ATT-drug and ayurvedic acute-liver-failure precipitants, and the lactulose / rifaximin / LOLA / TIPS / transplant treatment ladder.
Primary toxin
Ammonia (NH₃) from gut bacteria · Astrocyte swelling · Cerebral oedema (in acute HE) · Neuroinflammation.
HE Grades (ISHEN)
Grade 1: subtle cognitive impairment, sleep disturbance, personality change · Grade 2: flapping tremor (asterixis), disorientation, obvious behavioural change · Grade 3: confusion, somnolence, incoherent speech · Grade 4: coma (unresponsive, may or may not respond to pain).
Minimal HE (MHE)
Cognitive impairment detectable only by psychometric testing · No obvious clinical signs · Impairs driving, work performance, quality of life · Very common in cirrhosis (30–80%).
Precipitants — GEISMA
GI bleeding · Electrolyte abnormality (hyponatraemia, hypomagnesaemia) · Infection (SBP, UTI, pneumonia) · Surgery / procedure · Medications (sedatives, opioids, diuretics) · Aspiration/constipation.
Chronic liver causes in India
Hepatitis B (3.5–4% prevalence) · Hepatitis C (1% prevalence) · Alcohol-related liver disease · NAFLD/NASH · Wilson's disease · Autoimmune hepatitis.
Acute liver failure (ALF)
Wilson's disease, viral hepatitis, drug-induced (paracetamol in India is less common than in the West; more commonly anti-TB drugs: isoniazid + rifampicin + pyrazinamide) · Acute-on-chronic liver failure (ACLF).
Treatment
Lactulose (30–45 mL 2–3 times daily, titrate to 2–3 soft stools) · Rifaximin 550 mg twice daily · Treat precipitant · LOLA (L-ornithine L-aspartate) as adjunct · Zinc supplementation.
India note
Anti-TB drug-induced ALF · Ayurvedic hepatotoxicity (herbal remedies) · High viral hepatitis burden · Liver transplant available at KIMS.
Hepatic Encephalopathy — Ammonia-Driven Brain Dysfunction in Liver Failure
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome arising from liver failure or portosystemic shunting, in which neurotoxic substances that would normally be cleared by the liver accumulate in the systemic circulation and cross the blood-brain barrier. The principal neurotoxin is ammonia (NH₃), produced by gut bacteria from dietary protein and absorbed into the portal circulation. A healthy liver converts virtually all portal ammonia into urea via the urea cycle. When liver function fails — from cirrhosis, acute liver failure, or portosystemic shunting — ammonia bypasses the urea cycle and accumulates in the blood, reaching the brain where it disrupts astrocyte function, promotes cerebral oedema, impairs neurotransmission, and generates reactive oxygen species.
Hepatic encephalopathy is the most common cause of acute brain dysfunction in the setting of liver disease and represents a neurological emergency in its severe forms. In India, the burden of HE is substantial: viral hepatitis B and C, the most common causes of cirrhosis in India, together affect an estimated 50–60 million people, and alcohol- related liver disease and NAFLD/NASH add further to the cirrhosis burden. Most HE episodes are precipitated by an identifiable and treatable event — making rapid identification and correction of the precipitant central to management.
Emergency / Consultation
Speak directly with the KIMS hepatic encephalopathy team — all coordinated under one roof. Available 24 hours for acute presentations.
040-44885000Liver transplant available at KIMSMechanisms of Hepatic Encephalopathy
Ammonia and astrocyte dysfunction — the molecular mechanism
Ammonia that reaches the brain is metabolised almost exclusively by astrocytes (the brain's support cells) via glutamine synthetase — incorporating ammonia into glutamine. Excess glutamine accumulates within astrocytes, acting as an osmolyte: water follows, astrocytes swell (cytotoxic oedema), and in severe cases global cerebral oedema develops — which is the mechanism of intracranial hypertension and brain herniation in acute liver failure. Additionally, ammonia disrupts the blood-brain barrier, impairs mitochondrial function in astrocytes, and promotes neuroinflammation via microglial activation. The result is impaired neurotransmission across the brain, manifesting clinically as the graded encephalopathy of HE.
Asterixis — the liver flap of hepatic encephalopathy
Asterixis (liver flap or flapping tremor) is the characteristic motor sign of Grade 2 hepatic encephalopathy. It is demonstrated by asking the patient to hold their arms outstretched with wrists extended (dorsiflexed) — the wrists then show sudden brief lapses of sustained posture (negative myoclonus), producing a flapping movement. Asterixis is not a tremor (which is rhythmic) — it is the brief loss of motor tone from transient suppression of cortical motor output. Asterixis is not specific to HE (it can occur in uraemia, CO₂ retention, and other toxic-metabolic encephalopathies) but in the context of liver disease it is clinically invaluable. A patient with known cirrhosis who develops new asterixis has HE until proven otherwise.
Precipitants — identify and treat
In most patients with cirrhosis, the underlying liver disease alone does not cause HE — an acute precipitating event tips the balance. Identifying and correcting the precipitant is the most important management step. The KIMS HE assessment protocol examines: (1) GI haemorrhage (rectal exam, NG aspirate, endoscopy); (2) infection (blood / urine culture, ascitic tap for SBP); (3) electrolyte imbalance (Na, K, Mg, PO₄); (4) constipation; (5) excessive dietary protein or protein catabolism; (6) diuretic overuse; (7) sedatives or opioids (benzodiazepines potentiate GABA-A in already-sensitised HE); and (8) renal impairment.
ATT-Induced ALF and Ayurvedic Hepatotoxicity
Two India-specific causes of acute liver failure that shift the differential away from the Western paracetamol-dominated picture — drug-induced liver injury from the first-line ATT regimen (isoniazid + rifampicin + pyrazinamide, hepatotoxic in 5–20% of patients with a small fraction progressing to fulminant failure), and herbal / ayurvedic / siddha / unani / homeopathic preparations containing pyrrolizidine alkaloids, heavy metals or direct hepatotoxic botanicals that often go unreported unless directly and non-judgementally asked about.
Anti-tuberculosis drug-induced acute liver failure — the India-specific emergency
Drug-induced liver injury (DILI) from anti-tuberculosis (ATT) drugs is proportionally more common as a cause of acute liver failure in India than in Western countries, where paracetamol overdose dominates. The standard first-line ATT regimen (isoniazid + rifampicin + pyrazinamide) is hepatotoxic in approximately 5–20% of patients, and a small proportion develop fulminant hepatic failure. India's high tuberculosis burden means large numbers of patients are on ATT at any given time. Recognition: any patient on ATT who develops jaundice, confusion, or right upper quadrant pain should have liver function tests urgently · ATT must be stopped immediately if significant hepatotoxicity is confirmed · Re-challenge with a modified regimen is done cautiously after recovery.
Ayurvedic and herbal hepatotoxicity — the underreported cause
A significant proportion of acute liver failure cases in India are caused by herbal preparations, ayurvedic medicines, and dietary supplements — many of which contain pyrrolizidine alkaloids (from plants such as Heliotropium and Crotalaria), heavy metals (lead, mercury, arsenic in Rasa shastra preparations), or direct hepatotoxic botanical compounds. Patients often do not volunteer herbal preparation use when asked about medications. A direct, non-judgemental inquiry about all preparations taken — including ayurvedic, siddha, unani, and homeopathic medicines — is essential in any patient with unexplained liver failure.
Diagnosis at KIMS
Diagnosis at KIMS
Hepatic encephalopathy is diagnosed at KIMS with a structured workflow that begins with serum ammonia and bedside psychometric testing for minimal HE, and proceeds to a systematic emergency workup for the precipitant (LFTs, INR, electrolytes, blood and urine cultures, ascitic tap for SBP, upper GI endoscopy for bleeding, and EEG for non-convulsive seizures) :
Serum ammonia — a supportive marker, not a diagnostic test
Hepatic encephalopathy is a clinical diagnosis: neurological or psychiatric dysfunction in a patient with hepatic disease or portosystemic shunting, after other causes of encephalopathy have been excluded. Serum ammonia is measured to support a suspected diagnosis and to guide and monitor treatment, but it is not diagnostic on its own. A normal ammonia does not exclude HE — it can be normal in patients with definite clinical HE. An elevated ammonia does not confirm HE — it also rises with GI bleeding (bacterial degradation of blood protein), high dietary protein intake, urease-producing urinary infections, certain medications (valproate, chemotherapy), severe skeletal muscle breakdown, and inherited urea cycle disorders. The correlation with HE grade is imperfect in both directions. Practical points: venous or arterial sample transported on ice immediately · for minimal HE, psychometric testing (NCT-A, DST, or computerised tests) is more sensitive than ammonia levels. The diagnosis rests on the clinical picture, not the ammonia level.
Identify and treat precipitants — the primary intervention
Emergency labs: LFTs, INR, creatinine, electrolytes, ammonia, blood glucose, CBC, CRP · Blood and urine cultures · Diagnostic ascitic tap if ascites is present (SBP: PMN ≥250/mm³ in ascitic fluid) · Upper GI endoscopy if GI bleed suspected · EEG if non-convulsive seizures are suspected.
Lactulose — first-line treatment
Lactulose (non-absorbable disaccharide) reduces ammonia absorption from the gut by: acidifying the colon (converting NH₃ to NH₄⁺, which is not absorbed) · Increasing gut transit time · Altering gut flora. Dose: 30–45 mL 2–3 times daily, titrated to produce 2–3 soft stools per day. Excessive lactulose causing diarrhoea worsens dehydration and electrolyte imbalance — worsening HE. Enema form for Grade 3–4 patients who cannot swallow.
Rifaximin — second-line and prevention
Rifaximin 550 mg twice daily reduces gut ammonia-producing bacteria with minimal systemic absorption (no drug interactions). Used as add-on to lactulose for acute HE and as maintenance therapy for prevention of HE recurrence in cirrhotic patients with two or more prior episodes. LOLA (L-ornithine L-aspartate) is an adjunct that increases hepatic and peripheral ammonia clearance.
TIPS and liver transplant — for refractory and end-stage HE
TIPS (Transjugular Intrahepatic Portosystemic Shunt): reduces portal hypertension but can paradoxically worsen HE by increasing portosystemic shunting. Covered TIPS (ePTFE) with careful patient selection reduces HE risk. For patients with acute liver failure (ALF): liver transplant is the only definitive treatment and must be considered urgently when King’s College Criteria are met (paracetamol ALF: pH <7.3 or INR >6.5 + creatinine >300 + Grade 3–4 HE; non-paracetamol: INR >6.5 or 3 of: jaundice to encephalopathy >7 days, INR >3.5, bilirubin >300, unfavourable aetiology). KIMS has liver transplant capability.
Related Conditions
Hepatic encephalopathy belongs to the family of acquired brain injuries and metabolic encephalopathies evaluated and managed at KIMS Neuroscience.
FAQs
Frequently Asked Questions
Confusion in a patient with liver disease. Jaundice followed by disorientation. An ammonia result that does not match the clinical picture.
At KIMS Hyderabad, hepatology and neurology work together to identify the precipitant, restore consciousness, and prevent the next episode. For acute liver failure or sudden confusion: 040-46324365. For HE management and follow-up: 040-44885000.
International enquiries: info@kimsneurosciences.com