Intracranial Pressure Monitoring in

Intracranial Hypotension

Dr. Abhay Moghekar, M.B.,B.S.

Johns Hopkins University – School of Medicine

• Continuous ICP Monitoring Setup

• cICP in skull based CSF leaks

• cICP normative data in upright position

• cICP in spontaneous spinal CSF leaks

• cICP guided percutaneous intervention

• Units: 1 mm Hg = 1.3 cm of Water

Limitations of measuring opening

pressure during lumbar puncture

• Improper positioning, especially when performed under fluoroscopic guidance

• Diurnal variation, increased pressure with sleep-disordered breathing (apnea or hypopnea)

• Hyperventilation due to anxiety and/or pain lower ICP

• Pressures often normal in lateral decubitus position – not surprising since the majority of leak patients have abnormal pressures only during upright position when they are most symptomatic

•Direct measurement and graphic recording of intracranial pressure through

a trephined opening was described by LEYDEN in 1866.

•KEY & RETZIUS (1875) were the first to measure CSF pressure in animals,

and KNOLL (1886) produced the first graphic records CSF pressure

•Lumbar puncture as a clinical method introduced by QUINCKE in 1891

Then…

Bedside continuous CSF pressure monitoring

and

now…

Heart rate, EKG, respirations, and oxygen saturation are recorded in addition to CSFP referenced to the external auditory meatus. Signals are amplified and conditioned using a standard physiology monitoring system (Solar 8000M, GE Healthcare, Waukesha, WI). Analog voltages are sampled at 100 Hz and digital data are logged on a bedside computer (PowerLab data acquisition system and LabChart Pro software; ADInstruments, Colorado Springs, CO).

CSF Pressure values in mm H2O

measured @ LP*

Acute IIH Chronic IIH Normal Obese Normal Lean

Average 343.9 253 167 SD 36.46 136 SD37.6

Range 200-550(100%)

>250 (90%) >250 (28%)

200-250(44%) 200-250(25%)

<200 (28%)

*no sedation, local, 22-gauge needle, <1 ml of CSF loss,

left lateral decubitus,head and legs extended, pressure recorded for 1'

Revised Criteria: Adults: 5-25 cm, Children: 5-28 cm

Normal continuous Intracranial PressureChart Window

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2:56:40 AM 2:58:20 AM 3:00:00 AM 3:01:40 AM 3:03:20 AM 3:05:00 AM 3:06:40 AM 3:08:20 AM

Continuous ICP Monitoring – IIH

(LP opening pressure: 19 cm H2O)Chart Window

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Mean ICP > 20 mm Hg (26 cm H2O) for over 35 minutes

? IIHWOP, multiple shunts: Headache –

10/10, no papilledema, normal cICP recordingChart Window

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Skull based CSF Leaks

• CSF otorrhea and rhinorrhea can be congenital, post blunt head trauma, cranial or endoscopic surgery, or spontaneous

• Spontaneous idiopathic CSF leaks are 25–87% more likely to recur after surgical closure•Hubbard et al, Spontaneous cerebrospinal fluid rhinorrhea: Evolving concepts in diagnosis and surgical management based on the Mayo Clinic experience from 1970 through 1981. Neurosurgery 16:314–321, 1985•Ommaya et al, Nontraumatic cerebrospinal fluid rhinorrhea. J Neurol Neurosurg Psychiatr 31:214–215, 1968

• Pseudotumor cerebri and spontaneous CSF leak share common risk factors

CSF Otorrhea & Rhinorrhea

• Non-traumatic

cases have higher

incidence of

surgical failure

• Some have

findings of empty

sella - ?forme

fruste of PTC

CSF Otorrhea & Rhinorrhea -

preopChart Window

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CSF Otorrhea & Rhinorrhea –

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7:07:30 AM 7:08:20 AM 7:09:10 AM 7:10:00 AM 7:10:50 AM 7:11:40 AM

25% need Diamox postop and 5% shunts

Perioperative continuous cerebrospinal fluid pressure monitoring in patients with spontaneous cerebrospinal fluid leaks: Reh DD, Gallia GL, Ramanathan M, Solomon D, Moghekar A, Ishii M, Lane AP. Am J Rhinol Allergy. 2010 May-Jun;24(3):238-43.

Perioperative ICP management of

spontaneous skull based CSF Leaks

• Neuro-ophthalmology assessment

• Lumbar puncture

• Sleep study – mandibular advancement

device for OSA, NOT CPAP

• Lumbar continuous ICP Monitoring pre-

op and post-op

Perioperative continuous cerebrospinal fluid pressure monitoring in patients with spontaneous cerebrospinal fluid leaks. Xie YJ, Shargorodsky J, Lane AP, Ishii M, Solomon D, Moghekar A, Gallia GL, Reh DD. Int Forum Allergy Rhinol. 2015 Jan;5(1):71-7

What are normal intracranial (not lumbar)

pressures when upright ?

11 patients with hydrocephalus, posterior fossa tumors and aqueductal stenosis etc

Location matters

3-4 cm

What is normative CSF pressure in

the sitting/standing position

Author N Subjects Reference Range

Chapman-

Cossman8 patients Foramen of Monro -5 to +5 cm H2O

Loman 13 normals Cisterna magna -8.5 to +4.5 cm of H2O

Bradley 1 patient Convexity -16.5 cm H2O

Fox 18 patients Foramen of Monro -14 to +7 cm

Andresen 4 normals Convexity -10 to 0 mm Hg

Juhler 4 normals Convexity -9 to 0 mm Hg

What is low pressure?

Less than -10 mm Hg when monitored by

a parenchymal transducer in the cortex.

Supine

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2:19:00 PM 2:19:30 PM 2:20:00 PM 2:20:30 PM 2:22:00 PM 2:22:30 PM 2:23:00 PM 2:26:00 PM2829 30 32 33

8/27/2008 2:18:58.016 PM 8/27/2008 2:21:52.216 PM

SupineSitting Standing

Normal ICP change with position

ICP changes with sitting in a EDS patient with

no classic MRI brain findings over 60 mins

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Severe orthostatic headaches; negative imaging

Sitting up in bed

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CSF Leak s/p multilevel epidural blood/fibrin

patches with persistent orthostatic symptomsLabChart Reader Window

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Multi-level perineural cysts Day 1

baseline monitoring, sitting up

Day 2 after 4 multilevel blood/fibrin

patches

Day 3 after an additional 2 levels

were targeted

Spinal CSF Leak – baseline Day 1

monitoring - supine

Day 2 – post patch rebound

hypertension - supineMean CSFP was greater or equal to 19 mm Hg (about 25 cm water) for 27 mins (8.7% of the recording) and greater or equal to 15 mm Hg (about 20 cm water) for 64 (20.5%). Mean peak CSFP ranged from 9.3 to 42.5, with average mean peak CSF of 16.1. Mean peak CSFP was greater or equal to 25 for 25 minutes (8.0%). Mean waveform amplitude was 5.6, and ranged from 2.9 to 18.5. Mean waveform amplitude was greater than or equal to 5 for 142 minutes (45.5%).

LabChart Window

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2:28:10 AM 2:28:20 AM 2:28:30 AM 2:28:40 AM 2:28:50 AM 2:29:00 AM 2:29:10 AM 2:29:20 AM 2:29:30 AM

• Prior to endoscopic endonasal repair, a lumbar spinal catheter was inserted

• Overnight CSF pressure monitoring revealed CSF pressure greater or equal to 19 mm Hg 11% of the time.

• Mean CSF pulse waveform amplitude was greater than 5 mm Hg for 53.4% of the time.

• Lumbar drainage was performed for 3 days

• Overnight post-operative CSF pressure monitoring showed CSF pressure greater than 19 mm Hg only 5.6%

of the time.

• Positional CSF pressure testing was done…

Skull based CSF leak

A 61 year-old male with beta-2 transferrin positive left-sided rhinorrhea

BMI was 26.6, no clinical history of obstructive sleep apnea, meningitis, trauma, or sinonasal/cranial surgery.

• High-resolution CT showed left sided planum

sphenoidale defect

• T2-weighted MR demonstrated left sided

meningoencephalocele extending into the left

sphenoid sinus

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Supine CSF Pressure Recordings

Head right = 32.5 mm Hg

(44.2 cm H20)

Head left = 36.8 mm Hg

(50 cm H20),

Head neutral

Head leftHead right

Angiography demonstrates focal transverse venous sinus stenosis

Pre stent

Post stent

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5:26:30 PM 5:27:00 PM 5:27:30 PM 5:28:00 PM 5:28:30 PM 5:29:00 PM 5:29:30 PM 5:30:00 PM31 32 33 34 35 36 37 38 39

Post R transverse sinus stentPre stent

Eight months following stenting, the patient was weaned off acetazolamide and he remains

asymptomatic at 30 months follow up

Bilateral transverse sinus pressure gradient of

6.7 mm Hg across the areas of stenosis.

A 6 x 40 mm right transverse sinus stent was

then deployed in the right transverse sinus

Pressure gradients decreased to 0.4 mm Hg right

and 2.3 mm Hg left

One year following surgical leak repair he underwent a diagnostic

angiogram with cerebral venous sinus manometry

Venous Sinus Stenting in the Management of Patients with Intracranial Hypertension Manifesting with Skull Base Cerebrospinal Fluid Leaks. Iyer RR, Solomon D, Moghekar A, Goodwin CR, Stewart CM, Ishii M, Gailloud P, Gallia GL. World Neurosurg. 2017 Oct;106:103-112

ICP Monitoring in large Tarlov Cysts

with no radiographic signs of leakAge Diagnoses Upright pressure

(mm Hg)Orthostatic headache

58 Tarlov cyst. -13 Yes49 Sacral dural cyst -16 Yes41 Sacral cyst -14 Yes49 Marfan syndrome

Sacral dorsal ectasias -25 Yes

25 Tarlov cyst -10.7 Yes36 Tarlov cysts -7 Yes39 Tethered cord syndrome, Tarlov cyst -20 Yes31 Sacral cyst -12 Yes66 Large sacral internal meningocele -5 Yes42 chronic low back pain, sacral dural cysts,

infertility, bicornuate uterus.-13 Yes

34 Occult spina bifidaMeningocele

-4 Yes

cICP Implications post-treatment –

No straining……

Effects of CoughingLabChart Window

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Sleep Apnea related ICP elevations

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Practical Implications of cICP for

SIH post-treatment

• Sleep Apnea

• Body position

• Rebound intracranial hypertension

• Venous Stenosis

• Avoid futile treatment

• Guide appropriate treatment

Complications

• Scalp infection: <1%

• Seizures: <1%

ICP during a GTC Seizure –

exceeds CPP, O2 Sat dropsLabChart Window

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3:15:00 AM 3:20:00 AM 3:25:00 AM 3:30:00 AM 3:35:00 AM 3:40:00 AM22

Acknowledgments

Neurology

• Dr. Aruna Rao

• Dr. David Solomon

Neurosurgery

• Dr. Mark Luciano

Radiology

• Dr. Ferdinand Hui

• Dr. Majid Khan

• Dr. Ari Blitz

Neuroscience Nurses