Diagnostic Procedures
- Lumbar
Puncture
- Indications
include the diagnosis of meningitis, subarachnoid hemorrhage,
demyelinating disease, carcinomatous meningitis, spinal drop metastasis,
and dementia
- Contraindications
include acute spinal trauma, increased ICP secondary to a space-occupying
lesion, coagulopathy, presence of certain infectious processes (i.e.,
lumbar cellulitis)
- There
are few instances where prior head CT is not indicated
- Remember
to R/O coagulopathy (check coags, plts) prior to LP
- ALWAYS
obtain and record opening pressure
- ALWAYS
send fluid for cell counts, protein, glucose, cultures and sensitivities;
cytology, if indicated. Check for xanthochromia in patients with
suspected SAH.
- Cervical
tap is performed with patient supine and head straight. Puncture site is
1 cm. below and 1 cm. behind the tip of the mastoid process
- Queckenstedt
test may be used to detect partial/complete block. Jugular venous
compression for 10 sec will cause the pressure to rise at least 150 mm H2O
with return to baseline within 10-20 sec of release if there is no block
of the subarachnoid space
- Complications
include herniation, spinal HA, spinal fluid leak
- Petrosal
Sinus Sampling
- Selective
angiographic catheterization of petrosal sinus to collect blood specimens
for endocrine testing
- Used to
localize ACTH secreting pituitary lesions in Cushing’s disease
- Brain
Biopsy
- Indications
include diagnosis of intracranial lesions, rapidly progressing dementia
of unclear etiology, and to aid diagnosis of infectious processes
- May be
done stereotactically or as open biopsy
- Target
is area of abnormality on imaging
- If
imaging shows no clear abnormality, a right temporal lobe biopsy is
usually done
- Complications
are that of any intracranial procedure (hemorrhage, infection, neurologic
deficit (temporary or permanent), cerebral infarction)
- Nerve/Muscle
Biopsy
- Used in
diagnosis of neuropathy and myopathy
- Typical
sites are the dural nerve and gastrocnemius or quadriceps muscles
- Complications
include hemorrhage and/or wound infection
- Temporal
Artery Biopsy
- Used in
diagnosis of suspected arteritis
- Complications
include hemorrhage and/or wound infection
- Neuro-Ophthalmology
Evaluation
- Used to
document fundoscopic appearance, visual acuity, visual fields in patients
with lesions involving visual apparatus
- Cystometrogram
- Helpful
in diagnosis in patients with bladder dysfunction
- Neuro-Endocrine
Evaluation
- Essential
in management of sellar lesions
- Involves
the typical baseline endocrine function tests as well as dynamic
stimulation testing