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The timing of epidural analgesia is controversial. Although of epidural or spinal block, due to unpredictable changes in the
some propose initiation of the epidural block only when signs of epidural and spinal compartments, may not be well tolerated
AH are detected, most recommend a prophylactic epidural block in quadriplegics as they typically have no expiratory reserve
initiated at onset or during induction of labor.1,2,34,44,59,66 It is volume.51 Techniques that allow titration of local anesthetic
prudent to use dilute local anesthetic solutions to minimize are best: epidural catheters, spinal catheters, combined spinal“
hypotensive effects. An initial concentration and infusion rate of epidural (CSE).
bupivacaine for prevention of AH and provision of labor analgesia Nursing assistance is required to position and support the
is 0.080“0.125% at 8“10 ml/h. The rate can be altered to control patient for epidural and spinal insertion. Patient mobility and
pain or AH symptoms. Patient-controlled epidural analgesia is an presence of contractures or spasms will determine the best posi-
option for the parturient who needs analgesia. The role of lipid- tion. Once an epidural block is established the woman should be
soluble narcotics is uncertain, but if fentanyl is employed it repositioned every 30 to 60 minutes to prevent pressure sores.
should be used as an adjunct to local anesthetic as epidural There is no consensus on appropriate monitoring techniques
fentanyl alone was ineffective in one case report.70 Meperidine for the laboring SCI patient. Because of the low baseline BP and
has local anesthetic properties and can be given as a bolus of possibility of AH, routine use of invasive hemodynamic monitors
1 mg/kg epidurally or 0.25 mg/kg intrathecally to treat AH.2,71 (arterial line, central venous pressure) has been advocated.34 The
Adults with SCI are not at increased risk of latex allergy and author does not share this view and is of the opinion that non-
therefore do not require special protocols.72 invasive monitoring techniques are adequate in the majority of
cases.
Regional anesthesia in the cord-injured parturient
Anesthesia for cesarean section
Neither stable neurological disease nor a history of major spinal
surgery represent absolute contraindications to regional anesthe- The choice of anesthetic technique for C/S is influenced not only
sia. There may be technical difficulties in performing the block in by maternal condition and surgical procedure, but whether
parturients with abnormal anatomy, as well as an increased risk anesthesia is required for AH prophylaxis. These patients should
of accidental dural puncture or inadequate and failed blocks.73 be seen in consultation early in pregnancy to discuss anesthetic
Careful assessment of the upper end of the block is mandatory, as options, risk of AH, and to assess respiratory function. Regional
are frequent BP measurements. If the block is below the lesion block is required primarily to provide AH prophylaxis through
level it cannot be defined unless segmental abdominal reflexes visceral anesthesia in patients with high cord injury (above T5).
are intact. In those cases, lightly stroking the sides of the abdo- Encourage gentle surgical manipulation of the viscera to mini-
men above and below the umbilicus will initiate muscular con- mize the risk of an AH crisis. Avoid uterine exteriorization, if
traction causing the umbilicus to move towards the stimulus. possible. Postoperatively regional anesthesia is beneficial for AH
Regional blockade will stop this reflex activity. In patients with prophylaxis as well as providing analgesia. Spinal anesthesia may
spastic paraparesis, the level of the block becomes apparent with be technically easier to perform than epidural anesthesia but it is
loss of spastic activity.63 Invasive monitors are not required rou- harder to control anesthesia levels, hypotension may be more
tinely but may be indicated in specific situations. Pulse oximetry problematic, and respiratory mechanics may be impaired. Some
authors recommend against its use for these reasons.51,69
is recommended in patients with high cord lesions who are
receiving neuraxial opioids. Securing the epidural catheter ade- However, spinal block does provide consistently better sacral
anesthesia than epidural block.74,75
quately is essential due to increased sweating, secondary to AH. A
liquid adhesive and steri-strips along the epidural catheter in General anesthesia prevents AH when deep enough to prevent
addition to the usual dressing is usually effective. As AH may response to noxious genitourinary stimuli. Tracheal intubation
occur up to 48 hours postpartum, the epidural catheter should will not initiate AH. Rapidly acting i.v. antihypertensive agents
be left in situ postpartum.51 such as sodium nitroprusside and labetalol should be available.



194
Chapter 10


pain.79 The tumors are usually located anterolaterally, laterally, or
Succinylcholine is associated with massive hyperkalemia when
administered 72 hours post injury and up until six months or posterolaterally to the cord and most are completely intradural
and in the thoracic region.79,82 Surgery usually leads to a good
more after the injury. Hyperkalemia likely results from the pro-
liferation of extrajunctional neuromuscular receptors on the functional outcome, although younger patients with spinal
denervated muscle.40 Nondepolarizing muscle relaxants are meningiomas tend to have more aggressive histological subtypes
than patients older than 50 years.79
recommended for tracheal intubation and maintenance during
GA for all SCI patients in the first year post injury. There are six reported cases of spinal meningioma diagnosed
during pregnancy.80 In five of the six reported cases, surgery was
Patients with high cord lesions may require intensive manage-
ment and should be cared for in centers capable of offering such performed postpartum, and all had good to excellent neurological
treatment. Staff must be educated about the issues relating to recovery. All six patients had lower limb weakness and/or gait
instability at presentation.80
care of the SCI patients, in particular AH.
Astrocytoma, sarcoma, and ependymoblastoma have also been
reported.78,81 Metastatic tumors include melanoma, osteosarco-
Spinal cord tumors and vascular malformations
ma,83and invasive moles (see Figure 10.1).84,85
Spinal cord tumors are very rare in women of childbearing age, There are no guidelines regarding optimal delivery time for
representing less than 12% of nervous system tumors diagnosed women with spinal cord tumors; however, the need for radio-
during pregnancy. Less than 50 cases have been reported in the therapy or chemotherapy for malignant tumors influences the
literature and excluding vertebral hemagiomas, the majority are decision. Some tumors may progress rapidly, and even with sur-
benign lipomas, with an assortment of primary and metastatic gery the parturient may be left with significant spinal cord injury.
tumors comprising the remainder.76,77 Presenting symptoms of The same principles discussed earlier in managing SCI parturi-
spinal column and cord compression (back pain, fatigue, sciatica) ents should be applied.
may be attributed to the normal changes of pregnancy.77 Severe
and/or persistent back pain or neurological symptoms should be
investigated. Symptoms often worsen immediately postpartum,
and may be attributed to regional anesthesia.78 Diagnostic
imaging should not be delayed because of pregnancy, and radio-
graphic shielding should be maximized when possible. Magnetic
resonance imaging (MRI) is the preferred imaging method.76
Once the diagnosis is made, decompressive laminectomy and
tumor excision for nonvascular tumors should be performed
expeditiously to limit long-term neurologic deficits.77
Vascular malformations such as vertebral hemangiomas and
arteriovenous malformations (AVM) of the spinal cord are more
common than predicted from the number of symptomatic cases.
Spinal cord tumors are often confused with vascular malforma-
tions, as pregnancy increases vascularity of mengiomas and
hemangiomas. The physiologic impact of labor and delivery,
and the vascular and blood volume changes of pregnancy may
alter the course of the vascular malformation. There is little spe-
cific information about anesthetic management of these cases,
and common sense must apply to decisions regarding anesthetic
options for labor and delivery.


Primary and metastatic malignant tumors
Meningiomas are the most common reported cases of spinal cord
tumor occuring during pregnancy, usually comprising 25% of all
spinal cord tumors.79,80 Meningiomas, especially of the spinal
variety, are more common in women than men and some are
hormonally responsive.81 Spinal meningiomas are typically slow
growing; however, as they are frequently vascular pregnancy may
cause a sudden increase in size. There is no evidence that the
Figure 10.1 Metastatic invasive mole. Lumbar myelogram showing an
incidence of spinal meningiomas is increased by pregnancy, a extradural obstruction extending distally from the lower margin of the L4
preexisting one is simply more likely to become symptomatic.80 vertebral body. Reproduced with permission from Makangee, A., Nadvi,
Presenting symptoms of a spinal meningioma are: sensory S. S. & Van Dellen, J. R. Invasive mole presenting as a spinal extradural tumor:
changes (80%), gait instability (68%), and back pain or radicular case report. Neurosurgery 1996; 38:191“3.



195
3 Nervous system disorders


Benign tumors including neurofibromas spinal anesthesia for C/S in a patient with a known C3 spinal cord
AVM/angioma.97 Epidural anesthesia was avoided because of
Benign spinal cord tumors include cellular schwannomas, neu-
concerns about precipitating cord ischemia by a rise in epidural
rolemmomas, lipomas, and neurofibromas associated with von
space pressure. The associated commentary by two obstetrical
Recklinghausen disease.86,87,88,89,90 Typically these tumors are
anesthesiologists, however, suggested that spinal anesthesia
slow growing, and there is no evidence that they become more
(and epidural anesthesia) was not a safe option for spinal cord
symptomatic during pregnancy. There has been one case report
angioma/AVM.
each of cellular schwannoma and neurolemmoma diagnosed
There are approximately 17 reported cases of vertebral (bony)
during pregnancy. The women presented with back or hip pain
hemangiomas producing cord compressive symptoms during
with subsequent radiation into a leg.86,87 Both underwent surgical
pregnancy, the majority of them located in the upper thoracic
laminectomy postpartum with good neurological recovery.
regions of the spinal cord.95,98 Presentation is usually during the
Another woman presented two days postpartum with severe
third trimester, when the gravid uterus compresses the vena cava,
back pain. She had a thoracic neurinoma that had bled,
engorging the extradural venous plexus with a decrease in spinal
producing acute spinal cord compression.91 Her neurological
column perfusion pressure.99 One woman presented with leg
recovery was not complete despite early surgical intervention.
weakness and sensory loss immediately postpartum. The labor
Neurofibromas, associated with von Recklinghausen disease,
epidural was initially blamed, but clinical deterioration led to an
are discussed in Chapter 8.
MRI, which revealed a T11 compression fracture secondary to a
Spinal lipomas, intradural, not associated with spinal dysraph-
hemangioma (see Figure 10.2).95 Autopsy specimens of the gen-
ism, are very rare comprising less than 1% of all spinal tumors.
eral population reveal that 10% have undiagnosed angiomas of
There have been less than ten pregnancy-associated cases
the vertebral column.77 Symptoms often diminish or disappear
reported worldwide.89,90 These are slow-growing benign tumors
postpartum, so unless there is acute cord compression, some feel
that usually have a long history of vague sensorimotor distur-
it is reasonable to wait for fetal viability, perform a C/S, and then
bances prior to diagnosis and intervention, with spastic parapar-
reassess the need for surgical intervention.98 Hemangioblastomas
esis developing later. Three cases that presented peripartum had
of the spinal cord associated with von Hippel-Lindau disease are
symptoms ranging from two to twelve years previously, and all
located intramedullary, are of varying size, and may bleed during
deteriorated during pregnancy or shortly after delivery.89 Two of
pregnancy.100 Mode of delivery and use of regional anesthesia are
these women had midthoracic lesions, the other a cervicothor-
controversial in neurofibromatosis (see Chapter 8).
acic lipoma: all were located typically in the posterior aspect of
Similar to vascular spinal cord tumors, cardiovascular changes
the spinal cord. Diagnosis was made with computerized tomo-
during pregnancy, labor, and delivery may cause dural AVM to
graphy (CT) scan, followed by MRI. All patients underwent
become symptomatic. Dural AVM comprise approximately 5%
decompressive laminectomy postpartum: complete resection
of all spinal space-occupying lesions.101 Similar to angiomas,
of lipomas is not possible due to the close adherence to the
dural AVM often produce symptoms with exercise and certain
spinal cord.
postures.102 However, the symptoms are more likely to be gradual
There are a few cases of spinal hemangiolipomas presenting
in onset, as opposed to catastrophic, suggesting a bleed.101
during pregnancy. One patient was not diagnosed until nine years
Venous hypertension probably causes edema and secondary
postpartum when symptoms recurred, another patient was
ischemia of the spinal cord. The average age at presentation is
finally investigated following her tenth pregnancy despite symp-
57 years compared to 37 years for spinal cord angiomas, therefore
toms appearing during her ninth pregnancy.92 Both cases pre-
this vasular tumor is less likely to occur during pregnancy.102
sented with paraparesis during pregnancy and recovered
There is one case report of a cervical dural AVM (undiagnosed)
completely postpartum. The relapsing clinical picture is typical
becoming symptomatic with initiation of labor epidural analge-
for this kind of tumor.
sia. The theory is that epidural injection caused a change in blood
flow through the cervical AVM causing cord ischemia.103 There
are two reports of similar cord ischemia symptoms from an
Vascular tumors and other arteriovenous
undiagnosed thoracic dural AVM following the use of lumbar
malformations
epidural anesthesia,104,105 and one case following the use of
Angiomas and hemangiomas comprise the largest group of spinal anesthesia in an older male with a subsequently diagnosed
dural AVM.106 The consequences of an AVM bleed can be cata-
reported spinal cord tumors in pregnancy, and are overrepre-
sented compared to the general population.81 The theory is that strophic, requiring expeditious neurosurgical decompression.
the pregnancy-induced combination of increased blood volume However, dural AVM are less likely to bleed than spinal cord
angiomas.102
and venous pressure in the vertebral vascular plexus makes
angiomas clinically symptomatic.93,94 Symptoms are either sec- Differentiation between vascular tumors of the spinal cord and
ondary to compression or thrombosis/hemorrhage within the AVM of the dura or vertebral body has not been clear in the past
angioma.76,77 These vascular spinal tumors are likely to present due to poor quality imaging techniques and surgical/histological
in the third trimester.81,95,96 Symptoms may improve postpartum descriptions. Localization as intradural, extradural, or vertebral
and recur in a subsequent pregnancy if surgery was deemed may prove more useful in terms of risks of complications of
unnecessary.81 There is one case report of the successful use of compression and ischemia versus hemorrhage.



196
Chapter 10


Figure 10.2 Sagittal MRI of T11 vertebral fracture with spinal cord
compression due to vertebral hemangioma during pregnancy.
Image A is T1-weighted image. Image B is gadolinium enhanced.
Image C is T2-weighted. Reproduced with permission from
Schwartz, T., Hibshoosh, H. & Riedel, C. Estrogen and progesterone
receptor-negative T11 vertebral hemangioma presenting as a
postpartum compression fracture: case report and management.
Neurosurgery 2000; 46: 218“21.




Anesthetic management of the parturient with and anesthesia is recommended for these parturients. General
anesthesia is the recommended anesthetic technique.77
spinal cord tumors and AVM
Regional anesthesia/analgesia
Degenerative spinal cord diseases
Parturients who have had recent surgery on their vertebral col-
umn/neuroaxis may be unwilling to have neuraxial anesthesia.
Spinal muscular atrophy
Residual tumor, scarring, and inflammatory changes may make
regional techniques less reliable.83 There have been serious neu- Pathophysiology and effect on pregnancy
Spinal muscular atrophy (SMA) is a group of inherited, usually
rological sequelae following the use of regional anesthesia in
patients with occult or known spinal tumors,103,107,108 so most autosomal recessive, neuromuscular disorders in which the ante-
authors consider a spinal cord tumor to be a contraindication to rior horn cells of the spinal cord degenerate. The estimated inci-
the use of regional anesthesia.77,83,86,87 Those with known vascu- dence is 1:10 000 making it the second most common autosomal
lar malformations of the spinal cord should not have epidural or recessive disorder in Caucasians after cystic fibrosis. Type I
spinal anesthesia. Not only is there a risk of an epidural hema- (Werdnig-Hoffman disease) is the most severe form presenting at
birth with death usually within 2 years. Type II presents in child-
toma from direct trauma, but changes in cerebrospinal fluid
hood with rare survival to adulthood. Type III (Kugelberg-Welander
(CSF) pressure from a dural puncture or epidural bolus injection
disease) is the ˜˜mild, chronic™™ form of the disease. Most pregnant
may change the vascular wall stresses preciptitating hemorrhage
or edema with subsequent cord compression or cord ischemia. women with SMA have Type III disease; however, there are case
In addition, ˜˜normal™™ hypotension from spinal anesthesia may reports of pregnancy in Type II SMA, which typically means more
severe disease in the parturient.109,110,111,112 The classic features of
cause spinal cord ischemia from critical changes in perfusion
pressure or possibly a steal phenomenon.102,103 SMA are weakness and atrophy of the proximal muscles of the
lower limbs, more than the upper limbs, with fasciculations. Gait
Anesthesia for cesarean delivery instability is common, as are fine, irregular tremors of the upper
limbs. Most patients are wheelchair dependent by their third dec-
Elective C/S is usually chosen for parturients with spinal cord
ade in Type III disease, earlier in Type II. There are often significant
tumors or vascular malformations, because of the concern
about effects of labor on intra-abdominal and intrathoracic pres- respiratory effects due to involvement of the intercostal and acces-
sures with subsequent changes in blood flow in the tumor/ sory muscles of respiration. Secondary kyphoscoliosis may be
AVM.97 The paucity of cases in the literature, with the large severe, adding to the restrictive pulmonary defect; many women
variation in diagnosis and presentation, make it impossible will have undergone spinal instrumentation for scoliosis correc-
tion.113,114 Cranial nerve involvement is seen in less than 20% of
to draw a conclusion about the best mode of delivery. A case
patients with SMA. There is a case report of a parturient with SMA
conference involving consultants from neurosurgery, obstetrics,



197
3 Nervous system disorders


SMA who required invasive ventilatory support as pregnancy
progressed (see Figure 10.3).
Cesarean section is the mode of delivery in most cases, as
parturients with SMA may have a contracted pelvis and lack the
expulsive power to push.110,111,112,113,114,117,118,119 Postpartum
recovery is often prolonged in women with SMA, and overall
there is a high rate of complicated pregnancies and deliveries
(83% in Rudnik-Schoneborn™s series).116

Anesthetic considerations for labor and delivery
Both regional and general anesthesia have been used in SMA.
There are no contraindications to regional analgesia in this
chronic neurodegenerative disease; however, there are some
challenges. Previous spinal instrumentation can create techni-
cally challenging blocks, as well as a higher chance of inadeqate
or failed blocks.73,112,114,120 Continuous spinal anesthesia is an
option, providing a titratable block that is more likely to be com-
plete than epidural anesthesia. Epidurals, single-shot spinals, and
CSE have all been used or tried in these patients without subse-
quent deterioration in neuromuscular status.104,115,119,121
Positioning of the parturient for a regional technique can prove
challenging due to residual scoliosis and hip flexion contractures.
The degree of respiratory compromise must be considered
carefully prior to providing a high thoracic block, as removal of
already marginally functioning intercostal muscles may lead to
inability to cough or maintain an adequate tidal volume.122,123,124
Possible complications of GA in the parturient with SMA
include: prolonged neuromuscular blockade with subsequent
Figure 10.3 Antero-posterior plain x-ray postpartum showing severity of
need for ventilation, potential for acute hyperkalemia following
kyphoscoliosis and distorted intrathoracic contents in a woman with SMA Type II.
succinylcholine,125 and the effects of residual anesthesia plus
Reproduced with permission from Yim, R., Kirschener, K., Murphy, E. et al.
lower abdominal surgery on return of FVC in a patient with pre-
Successful pregnancy in a patient with spinal muscular atrophy and severe
existing respiratory compromise. Avoidance of neuromuscular
kyphoscoliosis. Am. J. Phys. Med. Rehabil. 2003; 82: 222“5.
blocking agents would be ideal.111

Type II and vocal cord paralysis.115 This woman had a forced vital
Amyotrophic lateral sclerosis
capacity (FVC) of 2.1 L, 54% of predicted value. She had a low
Pathophysiology and effect of pregnancy
forceps delivery with epidural analgesia, as she was unable to per-
Amyotrophic lateral sclerosis (ALS), also known as Lou-Gehrig
form Valsalva maneuvers due to the vocal cord paralysis.
disease, is a progressive neurodegenerative disease affecting the
Muscle weakness may worsen during pregnancy usually after
anterior horn cells of the spinal cord. It primarily affects men, and
the second trimester, and respiratory failure may occur necessi-
is typically diagnosed after the fifth decade of life with a preva-
tating ventilation. In a series of twelve patients with SMA, eight
lence of 2:100 000; however, there have been approximately 12
had worsening of muscle weakness after the second trimester,
cases reported since 1993 of pregnancy in women with ALS (see
and five reported permanent loss of muscular strength postpar-
Table 10.2).126,127,128,129,130,131,132 The incidence of ALS has been
tum.116 Unfortunately, anesthetic techniques were not discussed.
increasing, beyond that predicted for the aging population.
Respiratory function tests should be repeated in the third trim-
Multiple variants of ALS are now recognized, revealing consider-
ester to capture changes in respiratory function that may not be
able heterogeneity in the disease presentation and course.133
apparent in the wheelchair-bound patient. Yim described a suc-
Approximately 5“10% of cases are inherited as an autosomal
cessful pregnancy and delivery in a woman with SMA who had a
dominant gene. The median survival after diagnosis is 19 months,
FVC of 400 ml, severe kyphoscoliosis (1408 curvature), and body
and female sex is associated with worse disease.134 Typical symp-
weight of 31 kg.117 She did not require invasive ventilatory sup-
toms start with loss of fine motor function in the upper limbs,
port as the pregnancy progressed; however, she did require
fasiculations, and cramping. The disease progresses to involve the
increasing noninvasive ventilatory support. An elective C/S was
legs, followed by the muscles of the tongue, pharynx, and larynx.
performed at 34 weeks™ gestation as she could not eat adequately,
Higher cortical function remains intact. Parasympathetic activity
secondary to shortness of breath. Of note, she had a tracheost-
for bowel and bladder function remains relatively intact, as does
omy, which likely decreased her work of breathing compared to
ocular activity (see Table 10.3).
other published case reports of similarly affected parturients with



198
Table 10.2 ALS and pregnancy

Infant
Authors Age Pregnancy ALS onset ALS course during pregnancy Mode of delivery status ALS course postpartum

Levine, 1977 36 2nd 6th month GA: dysarthria, Slow progression SVD Healthy Slow deterioration
dysphagia, upper limb
weakness
38 3rd 2 years before Slow progression SVD Healthy Slow deterioration
MoretJurilli, 27 1st Prepregnancy. At time: severe Slight worsening C/S 39 weeks under spinal Healthy Not stated
1991 tetraplegia, dysarthria,
dysphagia
Lupo, 1993 28 3rd 36 weeks GA: R hip and foot Rapid worsening C/S Healthy Died 6 weeks
weakness postpartum
respiratory failure
33 5th 1 year prepregnancy: tetraplegia, No clinical worsening PROM 33 weeks. SVD Healthy Stable 1.5 years later
respiratory failure
Vincent, 1995 27 2nd 2 months prepregnancy Worsening. Appearance of bulbar C/S Healthy Stable
signs
Jacka, 1997 31 1st 8 weeks GA: lower limb weakness Worsening. Tetraparesis and C/S epidural Healthy Tracheostomy and PEG
respiratory failure at 32 weeks 1 week postpartum
Tyagi, 2001 29 1st 6th month GA: difficulty walking, Slight progression SVD Healthy Not stated
dysarthria
Chio, 2003 27 1st 6th month GA: weakness and Slight progression SVD epidural Healthy Progressive
atrophy hands, gait
29 1st 5th month GA: atrophy R Slight progression SVD Healthy Slight progression

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