Download Tara Engstrom

Abstract:
A 50-year-old Caucasian Male presents with complaints of headaches and
symptomatic constriction of peripheral visual field. Diagnostic MRI reveals
protrusion of the cerebellar tonsils into the spinal canal indicative of Chiari
Malformation Type 1.
I. Case History:
a. Patient Demographics: 50 year old Caucasian male; first presentation
2009 has been monitored and treated for Primary Open Angle
Glaucoma.
b. Chief Complaint: Presents to clinic for IOP check due to previous
POAG diagnosis; currently using Latanoprost qhs OU for IOP control.
Pt has noticed a decrease in peripheral vision and has difficulty with
orientation and mobility during daily activities.
c. Ocular/ Medical History:
i. (-)injury, (-)surgery, (-)family history of ocular conditions
- Diagnosed with POAG, OU in 2009
- Diabetes mellitus type II since 1999 without retinopathy, OU
–Hypertension
–Hypothyroidism
–Headaches – diagnosed by PCP as chronic and obstructive;
vague onset, frequency and location of headaches.
d. Medications:
– Latanoprost .005% qhs, OU
–Metformin HCL 500 mg PO BID
–Levothyroxine .2 mg PO BID
–Amlodopine 10 mg PO QD
–Vitamin B supplements (Pyridoxine HCL 25mg)
II. Pertinent Findings:
a. Clinical:
i. VA sc OD: 20/30-2, OS: 20/30
ii. PERRL –APD
iii. EOM FROM
iv. Confrontation fields – Severely and equally constricted OD, OS
v. SLE anterior segment: lids/lashes, conjunctiva, cornea, A/C,
Iris: WNL OU
vi. Angles 4/4 by VH OU
vii. Tap OD: 14, OS: 14 @250pm (last drop Latanoprost last night)
viii. DFE: Lens: trace NS OU, C/D ratios: OD: 0.60v/ 0.65h, deep;
OS: 0.60rd, deep, Macula: scattered hard fine drusen OU,
Vessels: normal 2/3 OU, Periphery: Flat and Intact 360 OU
No Diabetic Retinopathy, OU
b. Ancillary Testing:
•HVF 24-2 2/2009
–OD: Reliable; Superior Arcuate Defect
–OS: Reliable; Questionable Superior Arcuate Defect
•HVF 24-2 10/12/10
–OD: Severe Constriction; GHT ONL; VFI 43%
–OS: Severe Constriction; GHT ONL; VFI 31%
•rNFL OCT 10/12/10
–OD: Borderline superior and inferior thinning
–OS: Thinning Superiorly
**show images
c.
Radiology Studies:
a. MRI 10/2010: Chiari Type I malformation. Inferior surface of
the cerebellar tonsils is located approximately 5 mm below the
level of the foramen magnum.
b. MRI 11/01/ 2011: Chiari Type I malformation. Inferior
surface of the cerebellar tonsils is located approximately 5 mm
below the level of the foramen magnum; MRI consistent with
previous results.
**show images
III. Differential Diagnosis:
a. Primary/ Leading:
i. Migraines: Often associated with Chiari Malformations. MRI
and other imaging studies are the main differential. Imaging of
Migraine patients would show normal anatomical brain
structure versus a Chiari Malformation patient.
ii. Hydrocephalus: Increased Cerebrospinal Fluid; often presents
with similar symptoms and can be associated with Chiari
Malformation. MRI is the main differential to determine
whether protrusion of the brainstem is occurring. Hallmark
sign of Hydrocephalus on MRI is dilated ventricles.
b. Others:
i. Benign Intracranial Hypertension – Rule out disc edema on
fundus exam. If disc edema is present Chiari Malformation can
still be the cause. Thus imaging studies or lumbar puncture are
the gold standard to rule out other underlying conditions. BIH
is a diagnosis of exclusion.
ii. Primary Headache Syndromes – Usually duration and onset
can help rule out primary headache syndromes. Again to rule
out Chiari Malformation, imaging studies are warranted.
iii. Multiple Sclerosis – Inflammatory condition that attacks the
myelin sheathing of nerve axons. Presents with broad array of
symptoms including weakness, tingling, numbness, blurred
vision, and fatigue. True differential is an MRI and neurologic
exam.
iv. Spinal Tumors – Mass effect may cause comparable symptoms
as Chiari Malformation. MRI is used in differential diagnosis.
IV. Diagnosis and Discussion
a,b. Elaborate on the condition/ expound on unique features:
Chiari Malformations are a group of complex brain abnormalities that affect
the posterior base of the skull where the brain and spinal cord connect. Often
the posterior fossa is narrow and too small to hold the cerebellum and
brainstem. The cerebellum is forced downward resulting in protrusion
through the foramen magnum; this herniation of the cerebellum and
brainstem decreases CSF flow and can physically compress these areas of the
brain. Theories suggest improper fetal development associated with:
hazardous chemicals and substances, lack of vitamins and nutrients in
maternal diet, infection, prescription or illegal drug and alcohol consumption,
and hereditary tendency. There are four types of Chiari Malformations based
on their associated anatomical abnormalities.
Chiari Malformation Type I (CM1) is the most common and least severe. CM1
is typically congenital and presents in adulthood. CM1 is medically defined
as the displacement of the Cerebellar tonsils 5mm or more below the
foramen magnum as seen on imaging studies. Some common symptoms are:
•Chronic Headaches * most common symptom
–Cough, coital and exertion headaches
–Chronic Migraine; three times more prevalent in CM than in general
population
•Palatial Tinnitus and other auditory symptoms
•Neck pain – often radiating down the spine
•Dizziness/ Vertigo – increased with neck extension
•Vague pains throughout body
•Impaired balance and coordination
•Nausea/ vomiting
•Poor memory, cognition and concentration
•Polyuria
•Irritable bowel syndrome
•Difficulty Swallowing
•Changes in voice
Ocular Symptoms are:
•Photophobia
•Visual Blurring
•Peripheral field loss/ blind spots
•Downbeat Nystagmus
•Diplopia
•Mydriasis
•Papilledema
V. Treatment:
a. Treatment and response to treatment:
i. Surgical Intervention is the only treatment to correct a Chiari
Malformation. Some symptoms of this condition such as pain
and headaches can be medically treated with analgesics.
ii. New surgical studies have shown excellent success in the
improvement of quality of life of patients after the procedure.
iii. Goals of Surgery are to decompress the cervicomedullary
junction and restore CSF flow in the region of the foramen
magnum.
b. Refer to Research:
i. Retrospective study of 66 patients (mean age 15 years) – 32
patients presented with CM 1 alone and 34 patients in
combination with syringomyelia.
ii. Retrospective review of 25 patients with Chiari Malformation
and syringiomyelia with or without scoliosis were reviewed
over the past 20 years.
iii. Cerebrospinal Fluid flow imaging by phase- contrast MR
technique is being used to monitor CSF flow dynamics in
several disorders including Chiari Malformation and
hydrocephalus.
c. Bibliography:
1.Tisell M, Wallskog J, Linde M. Long-term outcome after surgery for Chiari I
malformation. Acta Neurol Scand 2009: 120: 295-299.
2.Verma R, Praharaj HN. Unusual association of Arnold- Chiari malformation
and vitamin B12 deficiency. Department of Neurology: 2012 July 09.
3.Chiari Malformation. http://emedicine.medscape.com. Updated March 2,
2012.
4.deSouza, Ruth-Mary, Zsolt Zador, David Frim. Chiari malformation type I:
related conditions. Neurological Research 2011: Vol. 33: 278- 284.
5.Cinalli G, Renier D, Sebag G. Chiari ‘malformation’ in Crouzon syndrome.
Arch Pediatr 1996; 3: 433-439.
6.Banik R, Lin D, Miller NR. Prevalence of Chiari I malformation and
cerebellar ectopia in patients with psuedotumor cerebri. J Neurol Sci 2006;
247: 71-75
7.Royo- Salvador MB. Syringomyelia, scoliosis and idiopathic Arnold-Chiari
malformations: a common etiology. Rev Neurol 1996; 24: 1241-50.
8.Kaplan Y, Oksuz E. Chronic migraine associated with the Chiari type I
malformation. Clin Neurol Neurosurg 2008; 110: 818 – 22.
9.Pettorini B, Gao A, Rodrigues D. Acute deterioration of a Chiari I
malformation: an uncommon neurosurgical emergency. Childs Nerv Syst
2011; 27: 857 – 860.
10.Alzate JC, Kothbauer KF, Jallo GI. Treatment of Chiari I malformation in
patients with and without syringomyelia: a consecutive series of 66 cases.
Neurosurg Focus. 2001 Jul 15; 11.
11.Chiari Malformation. http://www.wichiaricenter.org. The Wisconsin
Chiari Center. c 2012.
12.Chiari Malformation Fact Sheet. http://www.ninds.nih.gov. National
Institute of Neurologic Disorders and Stroke. Last updated 2/1/12.
13.Durai R, Fernandes C. Arnold- Chiari Malformation. Images in Medicine.
British Journal of Hospital Medicine, March 2010, Vol 71, No 3.
14.Chiari Malformations. http://www.webmd.com
15.Chiari Malformation. Columbia Neurosurgery.
http://www.columbianeurosurgery.com.
16.Chiari Malformation. The Chiari Institute.
http://www.chiariinstitute.com.
VI. Conclusion:
a. Clinical Pearls, take away points:
i. When symptoms of Chiari Malformations seriously impair the
patient’s quality of life, it is best to consider surgery.
ii. The goal of surgery for CM is to create more intracranial space
and improve CSF circulation.
iii. Physician should inquire regarding developmental history of
the child: Sitting up? Crawling? Walking? Talking? Also
measure the circumference of the head.
iv. No two cases of Chiari Malformation are alike.
v. MRI is the main diagnostic procedure for determining this
condition.