CNS Tuberculosis

Guide:Dr.SL Mathur sir

Presented by Dr.Pradeep2/7/20151

Introduction

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Tuberculosis, MTB, or TB (short for tubercle bacillus), in the past also

called phthisis, phthisis pulmonalis, or consumption.

Tuberculosis is the major cause of death worldwide.

Causative agent –mycobacteria tuberculosis.first isolated by Robert Koch in

1882 who received Nobel prize for this discovery

Neutral on gram staining, acid fast to 20% H2SO4

• CNS tuberculosis occurs in upto 10% of those infected and if untreated

carries high mortality.

Classification of neurotuberculosis

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• Intracranial

- Tuberculous meningitis

- Tuberculoma

- Tuberculous abscess

- Tuberculous encephalopathy

- Tuberculous vasculopathy

• Spinal

- Pott’s spine and Pott’s paraplegia

- Tuberculous arachnoiditis

- Spinal tuberculoma

- Spinal meningitis

Pathology

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• T lymphocyte dependent necrotising granulomatous inflammatory response.

• Thick gelatinous exudate.

• Three processes cause most of the neurological deficits:

Hydrocephalous

Adhesive arachnoiditis

Obliterative vasculitis

Tuberculous meningitis (TBM)

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• Commonest form of neurotuberculosis (70 to 80%) .

• TBM is also the commonest form of chronic meningitis.

• Clinical features include h/o vague ill health for 2-8 weeks prior to

development of meningeal irritation.

Contd…

Tuberculous meningitis (TBM) Contd…

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• Signs of Meningeal irritation.

• Cranial nerve palsies (20-30%)

• papilloedema or rarely choroid tubercles, seizures, focal neurological deficits secondary to infarction.

• Visual loss

• Increasing lethargy, confusion, stupor, deep coma, decerebrate or decorticate rigidity.

Investigations

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CBC,ESR,CXR-PA,LFT,RFT

HIV

CSF examination:

CSF Smear examination:

CSF culture on solid media: .

Adjunctive tests : .

Molecular diagnosis :

CT/MRI

Sensitivity & specificity of various

diagnostic tests for TBM

Menzies et al, Ann Int Med. 2007; 146: 340-354.

Diagnostic

test

Sensitivity Specificity

ZN staining 10-20% 100%

LJ Culture 15% (25-80) 100%

BACTEC Culture 55% 100%

ELISA 52.3% 91.6%

TB PCR 56% 98%

TST 73% 56%

QTF-GOLD 76% 98%

ELISPOT 87% 92%

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Test Appearance Pressure WBC/μL Protein mg/dL Glucose mg/dL

Chloride

Normal CSF Clear 90 – 180 mm 0-5lymph. 15-45 50-80 115-130 mEq/L

Acute bacterial meningitis

Turbid Increased 1000 -10000 100 – 500 < 40 Decreased

Viral meningitis

Clear Normal to moderate increase

5-300, rarely >1000

Normal to mild increased

Normal Normal

Tuberculous meningitis

Slightly opaque cobweb formation

Increased/ decreased,

100-600 mixed Initially neutrophillic & later lymphocytic

50-300 Decreased Decreased

Fungal meningitis

Clear Increased 40-400 mixed 50-300 Decreased Decreased

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Staging of TBM

Modified MRC criteria

Grade I: Alert and oriented (GCS 15) without focal

neurological deficit.

Grade II:GCS 14-10 with or without focal neurological

deficit or GCS 15 with focal neurological deficit.

Grade III: GCS less than 10 with or without focal

neurological deficit.

Diagnostic criteria for TBM

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Patients with at least four of the following:

i. History of tuberculosis.

ii. Predominance of lymphoytes in the cerebrospinal fluid.

iii. A duration of illness of more than six days.

iv. A ratio of CSF glucose to plasma glucose of less than 0.5.

v. Altered consciousness

vi. Turbid cerebrospinal fluid.

vii. Focal neurologic signs.

Possible

Patients with one or more of the following:

i. Suspected active pulmonary TB on chest radiography.

ii. AFB found in any specimen other than the CSF.

iii. Clinical evidence of extrapulmonary tuberculosis.

Probable

Acid-fast bacilli seen in the cerebrospinal fluid.Definite

DefinitionClass

Thwaites GE et al. Diagnosis of adult tuberculosis meningitis by use of clinical and laboratory features.

Lancet 2002; 360: 1287-92.

Management

Therapy:

Isoniazid – 5mg/kgd

Rifampicin – 10mg/kg/d

Pyrazinamide – 30mg/kg/d

Ethambutol – 15-25 mg/kg/d

Pyridoxine – 50mg/day

Ofloxacin-200mg BD

Dexamethasone for 8 weeks.

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Tuberculous brain abscess

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Tuberculous encephalopathy

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• Seen in infants and children.

• Characterized by convulsions, stupor and coma with signs of

meningeal irritation or focal neurological deficit.

Tuberculoma

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Spinal Tuberculosis

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Potts spine

Spinal form of tuberculous meningitis

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• May result from rupture of Rich foci in the spinal arachnoid space.

• The acute form presents with fever, headache, and root pains

accompanied by myelopathy.

• The chronic form presents with spinal cord compression.

WHO Recommended TB treatment

regimen

Drug regimens

Initial phase- first 2-3 months

During the initial phase, there is rapid killing of TB bacilli

Three or more drugs are used in combination

Infectious patients become non-infectious within about 2

weeks and symptoms usually improve

Continuation phase- additional 4-6 months

• Fewer drugs are necessary (usually 2), but longer time

• These drugs eliminate the remaining bacilli

Directly Observed Treatment Strategy (DOTS)

DOTS is a strategy for TB control which aims to detect 70 percent of

active TB cases and to successfully treat 85 percent of them2/7/201518

Anti-TB Drugs

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Antiretroviral Therapy for Individuals with

Tuberculosis Co infection

WHO guidelines:Recommendation for public health approach -2010

revision.

ART should be started in all TB patients, including drug-resistant TB,

irrespective of the CD4 count

AKT should be initiated first, followed by ART as soon as possible within the

first 8 weeks of treatment.

HIV-positive TB patients with profound immunosuppression (CD4 <50)

should receive ART immediately within the first 2 weeks of AKT .

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Adjunctive steroid therapy

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• The rationale behind the use of steroids includes the reduction of

inflammation within the subarachnoid space.

• The largest RCT in TBM recommends dexamethasone treatment in

patient with TBM for 8 weeks.

Thwaites GE et al. N Engl J Med 2004; 351: 1741-51;

Lancet Neurol 2007; 6: 280-6.

Role of surgery in CNS tuberculosis

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• Hydrocephalus

• Tuberculous cerebral abscess

• vertebral tuberculosis with paraparesis are all indications for

neurosurgical referral .

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