Page 169 Guide to Pain Management in Low-Resource Settings

Lung Cancer with Plexopathy 157

root). However, neuropathic pain might also be gener- However, descriptors such as burning, lancinating, or
ated by processing abnormalities in nociceptors. hot might be used as well. Other characteristics are pain
Common reasons for neuropathic pain in lung projection and pain radiation along a course of nerves
cancer are: with either segmental or peripheral distribution, when
• Compression or infi ltration of neurological the pain has a glove-like distribution, or is attributed to
structures, such as the brachial plexus, the chest a dermatome. Increasing pain when lying down, local-
wall, or intercostal nerves. Even though Pan- ized in the midline of the back with or without radia-
coast tumors are associated with only 3% of lung tion, and midscapular or bilateral shoulder pain might
cancers, more than 30% of all cancer-related be associated with neuropathic pain as well. Paresis or
pain syndromes in lung cancer are attributed to muscular weakness and pain of an upper extremity are
Pancoast tumors. Usually the pain of brachial strong evidence of a plexopathy.
plexopathy is felt as a burning sensation in the Screening tools such as painDETECT, an easy-
ulnar side of the hand, due to the involvement of to-use self-report questionnaire with nine items that
C7–T1 nerve roots. Another typical sign of bra- do not require a clinical examination, might be used
chial plexopathy is the occurrence of Horner’s as well. Patients have to answer seven questions re-
syndrome (miosis, ptosis, and enophthalmos), lated to the presence of burning sensations, tingling or
and pain is more intense as compared to pain prickling sensations, light touch being painful, the pres-
due to radiation therapy. ence of sudden pain attacks or electric shocks, cold or
• Treatment-related neuropathic pain syndromes heat pain, numbness, and slight pressure being pain-
may be the consequence of (major) surgery (e.g., ful. Th e scope of answers ranges from never, hardly
thoracotomy, installation of a therapeutic chest noticed, slightly, moderately, strongly, to very strongly
drain) and might cause a post-thoracotomy syn- and will be attributed a score of 0–5 each. Additionally
drome or intercostal neuralgia. Chemotherapy, persistent pain with pain attacks will reduce the total
especially after treatment with vinca alkaloids score (minus 1 point), pain attacks without pain in be-
such as vincristine, is another common reason tween will add 1 point, pain attacks with pain between
for treatment-associated neuropathic pain. Ra- them will add 1 point, and fi nally the presence of radia-
tion pain adds 2 more points. A fi nal sum score of 19
diation-induced plexopathy might be considered
or above strongly suggests the presence of neuropathic
as well. However, usually symptoms due to irra-
pain. PainDETECT has a specifi city and sensitivity of
diation occur with a latency of approximately 6
more than 80%. Alternatively the Leeds Assessment of
months or even later.
Neuropathic Symptoms and Signs (LANSS) tool might
• Paraneoplastic syndromes might present with
be used. Th is screening tool contains 5 symptom items
subacute or chronic sensory-motor neuropa-
and 2 clinical examination items (clinical examination
thy. Th ese syndromes are rare. Subacute sensory
for allodynia and pinprick threshold is necessary). Th e
neuropathy compromising all sensory modalities
sensitivity and specifi city is over 80% as well. Th is tool
preceding the diagnosis of cancer is often asso-
might also be used to show treatment eff ects.
ciated with small-cell lung cancer. Symptoms of
Th ese fi rst signs of the presence of neuropathic
paraneoplastic syndromes develop over days or
pain should be followed by a careful neurological ex-
weeks and might aff ect all four limbs, the trunk,
amination. Physicians should attend to somatosensory
and sometimes even the face.
abnormalities, such as dysesthesias, hyperalgesia, hyp-
esthesia, and allodynia. Most of these features can be
How can neuropathic pain diagnosed with simple bedside tests. Dysesthesia is an
be diagnosed? abnormal painful sensation (e.g., burning, lancinat-
ing pain). Using a stub-point needle, hyperalgesia—in-
A thorough medical history and examination are essen- creased perception of painful stimuli—can be diag-
tial. Th e patient’s description of the pain quality often nosed. Hypoesthesia describes a reduced feeling or an
provides a fi rst indication of the presence of neuropath- increased pain threshold (anesthesia stands for the non-
ic pain. Common verbal sensory pain descriptors are perception of a stimulus). Allodynia is defi ned as pain
throbbing, pricking, aching, tender, numb, and nagging. induced by a normally nonpainful stimulus.