1. Neurosurgical Investigations

2. Neurosurgical Investigations
Cerebrospinal fluid examination CSF
imaging study
Plain X-rays
CT scan
MRI
Cranial and Spinal Angiography.
Myelography
Positron emision tomography
MR spectroscopy
MR tractography
Electroencephalography (EEG).
Nerve conduction Studies/Electromyography (EMG).
Nerve and muscle biopsy
Hormonal tests

3. Cerebrospinal fluid(CSF) investigation
It can be obtained by
Spinal : lumber puncture LP
Cranial : lateral ventricular puncture
fluid can be accessed most safely in the lumbar cistern,
where the spinal cord has terminated into the cauda
equina (between the level of the first and second lumbar
vertebrae. The lumbar cistern extends into the sacrum.

6. Lumbar Puncture

8. Lumbar Puncture

9. Lumbar Puncture

10. Lumbar Puncture Indications
suspected meningitis
subarachnoid hemorrhage SAH
cytology in neoplastic diseases
measurement of intracranial pressure ICP
therapeutic CSF aspiration (benign raised intracranial pressure)(pseudotumor cerebri).
conventional myelography by contrast injection
Spinal anesthesia

11. Measurement of intracranial pressure

12. Contraindications to Lumbar Puncture
raised intracranial pressure other than pseudotumor cerebri . Features suggestive of raised ICP are
focal neurological deficit
recent seizure
papilloedema.
Sepsis at the site of LP
Bleeding tendency like coagulopathy and thrombocytopenia less than 50 × 109 /L
Abnormal respiration i.e. moribund patient
Vertebral deformities ( kyphosis and scoliosis )

13. Complications of lumbar puncture
Post spinal headache triad treatment
Cerebellar tonsillar herniation if there is raised ICP.
Injury to the neural structure
Back pain
infection and meningitis
Implantation of cutaneous tissue with subsequent epidermoid cyst
Bleeding

14. Imaging investigations
Plain X-rays
CT scan
MRI
Angiography.
Myelography
Positron emmision tomography
MR spectroscopy
MR tractography

15. Plain X-ray Skull X-ray: AP and lateral view
B. Plain X-rays of the spine:
X-rays of cervical spines
X-ray of thoracic (dorsal) spines
X-ray of the lumbosacral spines

16. The major abnormalities to look for on a skull X-ray are:
Fractures linear and depressed
Hyperostosis, e.g. meningioma.
Bone erosion due to skull vault tumours.
Abnormal calcification, e.g. tumours such as meningioma, oligodendroglioma, craniopharyngioma or calcified wall of an aneurysm.
Signs of long-standing raised intracranial pressure
erosion of the dorsum sellae
Double floor sella torcica
copper beating appearance of the skull vault.

26. Plain X-rays of the spine
Particular note should be taken of:
Vertebral alignment.
Presence of degenerative disease with narrowing of the neural foramina and spinal canal.
Evidence of metastatic tumour with erosion or sclerosis of the vertebral body, pedicles or lamina.
Enlargement of a neural foramen indicating a spinal schwannoma.
Congenital abnormalities such as spina bifida.

33. Computed Tomography (CT)Scan
Indications for Computed Tomography in Neurosurgery:
Cranial CT:
Diagnosis of acute neurosurgical lesions in the head and spine, including:
Skull and spinal fractures.
Intracranial hemorrhage: like extradural haematoma,subdural haematoma, intracerebral haematoma.
Oedema: brain oedema whether due to trauma or other cause.
Mass lesions: mainly brain mass lesions like tumours and brain abscess.
Hydrocephalus
Stroke: differentiate between infarction and intracranial haemorrhage.

35. Indications for Magnetic Resonance Imaging
Intracranial tumous.
cerebral abscess.
Arteriovenous malformations.
Venous sinus thrombosis.
Craniospinal abnormalities such as the Chiari malformation.
Syringomyelia.
Spinal tumours.
Disc prolapse (including cervical, lumbar and dorsal disc prolapse).
Spinal canal stenosis (lumbar or cervical stenosis) and cervical myelopathy.

37. CT is better than MRI
Diagnoses of bone related pathologies like fractures and bone tumors.
Better for acute hemorhagic lesions
Less time is needed to perform CT than MRI (few minutes)
critically ill patients.

38. MRI is better than CT
Sellar pathology (pituitary)
Posterior fossa tumours (cerebellar and brain stem tumours).
Spinal cord pathology (compression and tumours), and one can do myelography with non invasive method (no need for lumbar puncture).
Infarction can be diagnosed as early as few hours whereas CT needs 48 hours to diagnose it.
No ionizing radiation. Can be repeated safely

39. CT versus MRI

41. Contraindications to MRI
Metallic foreign bodies anywhere in the body like plating and screwing, shells ,cardiac pace maker, intracranial clips
Claustrophobia.
Gross obesity
Uncontrolled movement disorders (Parkinson’s disease).
Respiratory disease that require assisted ventilation or carry risk of apnea

42. Cranial and Spinal Angiography
images of blood vessels … arteriovenous malformations and aneurysms

46. Electroencephalography(EEG)
Diagnosis and follow up of epileptic patients with seizure focus localization
 sleep disorders, coma, encephalopathies.
 To differentiate epileptic seizures from other types of spells, such as psychogenic non-epileptic seizures
to characterize seizures for the purposes of treatment

47. Electroencephalography(EEG)

48. Nerve conduction studies/ Electromyography(EMG)
Carpal tunnel syndrome
Guillain-Barré syndrome
Peripheral neuropathy
Spinal disc herniation

49. Nerve conduction studies/ Electromyography(EMG)

50. Nerve conduction studies/ Electromyography(EMG)

51. positron emission tomography PET
A positron emission tomography (PET) scan is an imaging test that can map tissue biochemistry and physiology i.e functional test
The most commonly used PET tracer being a labeled form of glucose ( Fludeoxyglucose (18F) (FDG).
Useful in differentiating ischemic from neoplastic areas.

54. MR spectrography
non-invasive, ionizing radiation free analytical technique that has been used to study metabolic changes in brain tumors, strokes, seizure disorders, Alzheimer's disease, depression and other diseases affecting the brain.

55. MR tractography
Visual representation of neural tracts

56. Nerve and muscle biopsy

57. Hormonal assay