Neuro Pathology
• Neurons: functional unit of the brain and sets off the AP, sits in grey matter in
peripheries
• Glial cells: neuronal support cells, grey and white matter
o Astrocytes: maintain homeostasis (ion balance, nutrients)
o Oligodendrocytes: coat neuronal axons with insulating substance myelin
§ Slightly smaller darker and rounded nuclei
o Ependymal cells: ciliated simple columnar cells which line cavities of CNS,
secrete and help circulate CSF (froms the choroid plexus)
The most sensitive part of the spinal cord is the dorsal root ganglia
Raphe nucleus is the main area producing serotonin in the brain
Best brain death imaging modality tool: HMPAO SPECT scan (nuclear
imaging using gamma rays) used to measure the amount of blood flow
in capillaries of the imaged regions
• Radiopharmaceutical:
o Sestamibi (technetium 99): myocardial perfusion scan,
parathyroid scan
o HMPAO (technetium 99): brain scan
o MIBG (iodine 123 or 131): Neruoendocrine/neurological
tumour scan
,Parts of brain:
1. Telencephalon: Cerebrum
a. Cerbral hemispheres: surface contain gyri and sulci
b. Each hemisphere has 5 lobes:
i. Frontal: anterior superiorly
ii. Parietal: Posterior superiorly
iii. Temporal: inferior to transverse alteral sulcus
iv. Occipital: posteirorly
v. Insula/limbic: medial to temporal lobe and influences emotions and
autonomic functions
2. Diencephalon: central core of the brain
a. Epithalamus
i. Roof of 3rd ventricle
ii. Pineal gland at Posterior end
b. Thalamus:
i. Superolateral wall of 3rd ventricle
, ii. Relay station for afferent info: All afferent fibres converge to be
sorted and edited, synapse at at least 1 nuclei
c. Hypothalmus:
i. Inferolateral wall of 3rd ventricle (below thalamus)
ii. Extend from optic chiasm and ammillary bodies to midbrain
iii. Function:
1. Autonomic control center
2. Center for emotional response: heart of limbic system
3. Regulation of food intake, thirst, body temperature, sleep
wake cycles
4. Control of endocrine functioning
3. Mesencephalon: Mid brain
a. Rostral part of brain stem
b. Lies at junction of middle and psoteiror cranial fossae
c. Cerebral peduncles (CST) and Superior cebellar peduncles
d. Copra quadrigemina: 4 protrusions on dorsal midbrain
i. 2 superior colliculi
ii. 2 inferior colluculi
e. 2 pigmented nuclei
i. Substantia nigra
ii. Red nucleus
4. Metencephalon: Pons/cerebellum
a. Deals with cranial nerve V
b. Coordination and balance functions (DANISH)
5. Myelencephalon: medulla
a. Most caudal subdivision of brainstem
b. CN 6, 7, 8 are at pons-meduallry juction
c. CN 9, 10, 12 exits here
d. CN 11 is from upper spinal cord
e. Visceral motor nuclei
Neural crest cells derivatives: MOTEL PASS
• Melanocytes
• Odontoblasts
• Tracheal cartilage
• Enterochromaffin cells
• Laryngeal cartilage
• Parafollicular C cells/psudounipolar cells/parasympathetic ganglia
• All ganglia/adrenal medulla
• Schwnn cells
• Spinal membrane
Brainstem rules of 4:
• 4 structures in midline (M)
o Motor pathyway: corticospinal tracts (contralateral weakness)
o Medial lemniscus: contralateral vibration and proprioception
o Medial longitudinal fasiculus: contralateral internuclear ophthalmoplegia
o Motor nucleus and nerves: ipsilateral loss of CN 3, 4, 6, 12
• 4 structures to the side (S)
o Spinothalamic tract: contralateral pain and temperature
o Sympathetic (descending) tract: Ipsilateral loss of SNS (Horner’s syndrome)
o Spinocerebellar: ipsilateral ataxia UL and LL
o Sensory nucleus of trigeminal: ipsilateral alteration of pain and temperature in
face
• 4 cranial nerves In medulla, 4 in pons, 4 in midbrain
• 4 motor nuclei in midline: CN 3, 4, 6, 12
Neurosurgery:
, • All about prognostication: QoL, functional status (and NOT just about life saving
• Initiate correction if:
o sBP<90mmHg
o Hypoxia <60mmHg
• ICP threshold is 22mmHg before intervention is initiated
• Anticoagulation:
o Always reverse all anticoagulant or antiplatelet as soon as possible
§ Unfortunately this increases the risk of thrombosis and cannot be
avoided
§ Options:
• Tranexamic acid
• Prothrombinex
• Platelet transfusion: Will need TDS transfusion especially for
aspirin since it takes 5d for platelets to regenerate
o Bleeding in the brain cannot be charred/diathermy.
o However, spinal cord can be charred/diathermy
• TBI treatment recommendations
o Decompressive craniectomy:
§ Bifrontal DC is NOT recommended
• Note: if you remove the dominant frontal lobe, you disinhibit
the patient
• If you remove the non-dominant frontal love, patient become
severely depressed
• If both frontal lobes are removed, patient become severely
depressed
§ A large frontotemporoparietal DC is recommended
o Hypothermia (early: 2.5h or short term: 48h) is NOT recommended
o Mannitol 0.5g/kg is effective for control of raised ICP
o CSF drainage with EVD is effective in lowering ICP burden
o Prolonged prophylactic hyperventilation with PaCO2<25mmHg is NOT
recommended as it can compromise cerebral perfusion
§ Hyperventilation is a good temporizing measure for reduction of
elevated ICP but only to a normocarbia level
o High dose barbiturates is recommended to control elevated ICP
refractory to maximum standard mediacal/surgical treatment.
Haemodynamic stability is essential before and during barbiturate
therapy
§ Propofol is recommended for control of ICP but not recommended for
improvement in mortality or 6m outcomes
o Steroids is NOT recommended for improving outcome or reducing ICP
o Nutrition to attain basal caloric replacement at least by 5th day and at
most 7th day post injury is recommended to decrease mortality
§ Transgastric jejunal feeding is recommended to avoid ventilator
associated pneumonia
o DVT prophylaxis:
§ LMWH: start at 48h for low risk patients, 5-7days post injury
automatically
§ Start mechanical prophylaxis immediately
§ IVC filter for high risk trauma patients
o Seizure prophylaxis:
§ Phenytoin (300mg every 6 hours for 3 doses and then 100mg
TDS) or Keppra (500mg BD) for 1/52
o ICP monitoring is recommended to reduce hospitalisaiton duration and
2 week post injury mortality
§ ICP threshold is >22mmHg
o CPP monitoring is recommended to decrease 2 week mortality
§ Recommended between 60-70mmHg, avoid aggressive attempts
to maintain above 70mmHg
o sBP should be maintained at:
§ 100mmHg or more for patients 50-69yo
• Neurons: functional unit of the brain and sets off the AP, sits in grey matter in
peripheries
• Glial cells: neuronal support cells, grey and white matter
o Astrocytes: maintain homeostasis (ion balance, nutrients)
o Oligodendrocytes: coat neuronal axons with insulating substance myelin
§ Slightly smaller darker and rounded nuclei
o Ependymal cells: ciliated simple columnar cells which line cavities of CNS,
secrete and help circulate CSF (froms the choroid plexus)
The most sensitive part of the spinal cord is the dorsal root ganglia
Raphe nucleus is the main area producing serotonin in the brain
Best brain death imaging modality tool: HMPAO SPECT scan (nuclear
imaging using gamma rays) used to measure the amount of blood flow
in capillaries of the imaged regions
• Radiopharmaceutical:
o Sestamibi (technetium 99): myocardial perfusion scan,
parathyroid scan
o HMPAO (technetium 99): brain scan
o MIBG (iodine 123 or 131): Neruoendocrine/neurological
tumour scan
,Parts of brain:
1. Telencephalon: Cerebrum
a. Cerbral hemispheres: surface contain gyri and sulci
b. Each hemisphere has 5 lobes:
i. Frontal: anterior superiorly
ii. Parietal: Posterior superiorly
iii. Temporal: inferior to transverse alteral sulcus
iv. Occipital: posteirorly
v. Insula/limbic: medial to temporal lobe and influences emotions and
autonomic functions
2. Diencephalon: central core of the brain
a. Epithalamus
i. Roof of 3rd ventricle
ii. Pineal gland at Posterior end
b. Thalamus:
i. Superolateral wall of 3rd ventricle
, ii. Relay station for afferent info: All afferent fibres converge to be
sorted and edited, synapse at at least 1 nuclei
c. Hypothalmus:
i. Inferolateral wall of 3rd ventricle (below thalamus)
ii. Extend from optic chiasm and ammillary bodies to midbrain
iii. Function:
1. Autonomic control center
2. Center for emotional response: heart of limbic system
3. Regulation of food intake, thirst, body temperature, sleep
wake cycles
4. Control of endocrine functioning
3. Mesencephalon: Mid brain
a. Rostral part of brain stem
b. Lies at junction of middle and psoteiror cranial fossae
c. Cerebral peduncles (CST) and Superior cebellar peduncles
d. Copra quadrigemina: 4 protrusions on dorsal midbrain
i. 2 superior colliculi
ii. 2 inferior colluculi
e. 2 pigmented nuclei
i. Substantia nigra
ii. Red nucleus
4. Metencephalon: Pons/cerebellum
a. Deals with cranial nerve V
b. Coordination and balance functions (DANISH)
5. Myelencephalon: medulla
a. Most caudal subdivision of brainstem
b. CN 6, 7, 8 are at pons-meduallry juction
c. CN 9, 10, 12 exits here
d. CN 11 is from upper spinal cord
e. Visceral motor nuclei
Neural crest cells derivatives: MOTEL PASS
• Melanocytes
• Odontoblasts
• Tracheal cartilage
• Enterochromaffin cells
• Laryngeal cartilage
• Parafollicular C cells/psudounipolar cells/parasympathetic ganglia
• All ganglia/adrenal medulla
• Schwnn cells
• Spinal membrane
Brainstem rules of 4:
• 4 structures in midline (M)
o Motor pathyway: corticospinal tracts (contralateral weakness)
o Medial lemniscus: contralateral vibration and proprioception
o Medial longitudinal fasiculus: contralateral internuclear ophthalmoplegia
o Motor nucleus and nerves: ipsilateral loss of CN 3, 4, 6, 12
• 4 structures to the side (S)
o Spinothalamic tract: contralateral pain and temperature
o Sympathetic (descending) tract: Ipsilateral loss of SNS (Horner’s syndrome)
o Spinocerebellar: ipsilateral ataxia UL and LL
o Sensory nucleus of trigeminal: ipsilateral alteration of pain and temperature in
face
• 4 cranial nerves In medulla, 4 in pons, 4 in midbrain
• 4 motor nuclei in midline: CN 3, 4, 6, 12
Neurosurgery:
, • All about prognostication: QoL, functional status (and NOT just about life saving
• Initiate correction if:
o sBP<90mmHg
o Hypoxia <60mmHg
• ICP threshold is 22mmHg before intervention is initiated
• Anticoagulation:
o Always reverse all anticoagulant or antiplatelet as soon as possible
§ Unfortunately this increases the risk of thrombosis and cannot be
avoided
§ Options:
• Tranexamic acid
• Prothrombinex
• Platelet transfusion: Will need TDS transfusion especially for
aspirin since it takes 5d for platelets to regenerate
o Bleeding in the brain cannot be charred/diathermy.
o However, spinal cord can be charred/diathermy
• TBI treatment recommendations
o Decompressive craniectomy:
§ Bifrontal DC is NOT recommended
• Note: if you remove the dominant frontal lobe, you disinhibit
the patient
• If you remove the non-dominant frontal love, patient become
severely depressed
• If both frontal lobes are removed, patient become severely
depressed
§ A large frontotemporoparietal DC is recommended
o Hypothermia (early: 2.5h or short term: 48h) is NOT recommended
o Mannitol 0.5g/kg is effective for control of raised ICP
o CSF drainage with EVD is effective in lowering ICP burden
o Prolonged prophylactic hyperventilation with PaCO2<25mmHg is NOT
recommended as it can compromise cerebral perfusion
§ Hyperventilation is a good temporizing measure for reduction of
elevated ICP but only to a normocarbia level
o High dose barbiturates is recommended to control elevated ICP
refractory to maximum standard mediacal/surgical treatment.
Haemodynamic stability is essential before and during barbiturate
therapy
§ Propofol is recommended for control of ICP but not recommended for
improvement in mortality or 6m outcomes
o Steroids is NOT recommended for improving outcome or reducing ICP
o Nutrition to attain basal caloric replacement at least by 5th day and at
most 7th day post injury is recommended to decrease mortality
§ Transgastric jejunal feeding is recommended to avoid ventilator
associated pneumonia
o DVT prophylaxis:
§ LMWH: start at 48h for low risk patients, 5-7days post injury
automatically
§ Start mechanical prophylaxis immediately
§ IVC filter for high risk trauma patients
o Seizure prophylaxis:
§ Phenytoin (300mg every 6 hours for 3 doses and then 100mg
TDS) or Keppra (500mg BD) for 1/52
o ICP monitoring is recommended to reduce hospitalisaiton duration and
2 week post injury mortality
§ ICP threshold is >22mmHg
o CPP monitoring is recommended to decrease 2 week mortality
§ Recommended between 60-70mmHg, avoid aggressive attempts
to maintain above 70mmHg
o sBP should be maintained at:
§ 100mmHg or more for patients 50-69yo
