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Toronto Notes 2019 Cerebral Abscess Neurosurgery NS15
• endocrineeffects(seeEndocrinology,E20)
■ hyperprolactinemia (prolactinoma): infertility, amenorrhea, galactorrhea, decreased libido ■ ACTH production: Cushing’s disease, hyperpigmentation
■ GH production: acromegaly/gigantism
■ panhypopituitarism: due to compression of pituitary (hypothyroidism, hypoadrenalism,
hypogonadism)
■ diabetes insipidus (DI) – rare, except in apoplexy
• pituitaryapoplexy(suddenexpansionofmassduetohemorrhageornecrosis)
■ abrupt onset H/A, visual disturbances, ophthalmoplegia, reduced mental status, panhypopituitarism
andDI 1
■ CSF rhinorrhea and seizures (rare)
■ signs and symptoms of subarachnoid hemorrhage (rare)
2
Investigations 54 3
©Kaia Chessen 2017
• formal visual fields, CN testing
• endocrinetests(prolactinlevel,TSH,8AMcortisol,fastingglucose,FSH/LH,IGF-1),electrolytes,urine
electrolytes, and osmolarity
• imaging(MRIwithandwithoutcontrast)
Treatment
• medical
■ for apoplexy: rapid corticosteroid administration ± surgical decompression
■ for prolactinoma: dopamine agonists (e.g. bromocriptine)
■ for Cushing’s: serotonin antagonist (cyproheptadine), inhibition of cortisol production
(ketoconazole)
■ for acromegaly: somatostatin analogue (octreotide) ± bromocriptine ■ endocrine replacement therapy
• surgical
■ endoscopic trans-sphenoidal, trans-ethmoidal, and less commonly trans-cranial approaches (i.e. for
significant suprasellar extension)
• post-operativeconcerns:DI,adrenalinsufficiency(AI),CSFleak
■ DI and AI: AM cortisol, serum sodium and osmolality, urine output and specific gravity (treatment - AI: glucocorticoids; DI: desmopressin/DDAVP)
■ CSF rhinorrhea: test for β transferrin
Cerebral Abscess
Definition
• pusinbrainsubstance,surroundedbytissuereaction(capsuleformation)
Etiology
• modesofspread:10-60%ofpatientshavenocauseidentified • pathogens
■ Streptococcus (most common), often anaerobic or microaerophilic ■ Staphylococcus (penetrating injury)
■ Gram-negatives, anaerobes (Bacteroides, Fusobacterium)
■ in neonates: Proteus and Citrobacter (exclusively)
■ immunocompromised: fungi and protozoa (Toxoplasma, Nocardia, Candida albicans, Listeria monocytogenes, Mycobacterium, and Aspergillus)
Sources of Pus/Infection
• fourroutesofmicrobialaccesstoCNS
1. hematogenous spread: arterial and retrograde venous
◆ adults: chest is #1 source (lung abscess, bronchiectasis, empyema) ◆ children: congenital cyanotic heart disease with R to L shunt
◆ immunosuppression (AIDS – toxoplasmosis)
2. direct implantation (dural disruption) ◆ trauma
◆ iatrogenic (e.g. following LP, post-operative)
◆ congenital defect (e.g. dermal sinus)
3. contiguous spread (adjacent infection): from air sinus, naso/oropharynx, surgical site (e.g. otitis
media, mastoiditis, sinusitis, osteomyelitis, dental abscess) 4. spread from PNS (e.g. viruses: rabies, herpes zoster)
• commonexamples
■ epidural abscess: in cranial and spinal epidural space, associated with osteomyelitis
◆ treatment: immediate drainage and antibiotics, surgical emergency if cord compression
■ subdural empyema: bacterial/fungal infection, due to contiguous spread from bone or air sinus,
progresses rapidly
◆ treatment: surgical drainage and antibiotics, 20% mortality
■ meningitis, encephalitis (see Infectious Diseases, ID18)
■ cerebral abscess
7 68 9
10
1. Anterior cerebral artery
2. Internal carotid artery (cerebral part) 3. Pituitary gland
4. Oculomotor nerve
5. Trochlear nerve
6. Internal carotic artery (cavernous part) 7. Ophthalmic nerve
8. Abducent nerve
9. Cavernous sinus
10. Maxillary nerve
Figure 14. Cavernous sinus