Case #1: Excruciating neck pain and headache caused by hypophysitis
A 40-year-old woman was enrolled in a double-blind clinical trial comparing adjuvant ipilimumab and nivolumab versus nivolumab monotherapy in patients with metastatic melanoma. After 2 months, the patient complained of new and intense neck pain, holocephalic headache and signs of fatigue. The neurological examination was unremarkable. Her medical history was negative for signs of a primary headache disorder. Cervical and cerebral magnetic resonance imaging (MRI) scans showed no significant changes. Laboratory work up revealed autoimmune hypophysitis with adrenal insufficiency. Hormone replacement therapy was immediately initiated, including an intravenous (i.v.) prednisolone bolus (100 mg), followed by hydrocortisone substitution (30 mg daily) and slow tapering to 15 mg daily (table 1). The neurological symptoms rapidly and completely resolved. Ten days later, blood analysis revealed thyroid dysfunction. The pituitary dysfunction continued for several months; therefore, chronic hypophysitis was diagnosed. However, neurological symptoms did not recur.
Case #2: Bilateral facial nerve palsy in a case of Guillain-Barré syndrome
A 72-year-old man with melanoma was treated within the same adjuvant trial as in Case #1. Owing to pulmonary and cerebral disease progression, treatment within the trial was stopped. The patient was switched to combination immunotherapy with ipilimumab (3 mg/kg) and nivolumab (1 mg/kg). After the third infusion of combination therapy, he presented with slurred speech and incomplete eye lid closure due to bilateral facial nerve palsy. Five to 6 weeks before symptom onset, he experienced a few days of fever, headache, adynamia and loss of appetite. An examination revealed mild deep tendon reflexes and loss of the Achilles’ tendon reflex, positive Romberg’s sign and mild dysmetria of the upper extremities. Electrophysiological studies revealed prolonged F-wave latencies in several nerves, A-waves, reduced nerve conduction velocity and prolonged distal motor latency delay consistent with demyelinating polyneuropathy (Figure 1). The cerebrospinal fluid (CSF) had pleocytosis (20 leukocytes/µL) and an elevated protein level (98 mg/dL). Inflammation and meningeal carcinomatosis were absent in cranial MRI studies.
For 3 consecutive days, methylprednisolone (1 g i.v.) was administered daily. His symptoms rapidly improved and therapy was continued with intravenous immunoglobulin (IVIG).
Case #3: Transverse myelitis
In 2015, a 55-year-old man was diagnosed with malignant melanoma with cervical and pulmonary metastasis. At that time, he was treated with ipilimumab. After the second infusion and 2 months after initiating ICI therapy, the patient complained of sudden loss of sensibility in his hands, gluteal region and legs, primarily on the left side, and weakness of his left hand. Neurological examination showed exaggerated deep tendon reflexes, clonus of the lower extremity and weakness in his left lower and in both upper extremity. He presented hypoesthesia in dermatomes C5–T1 on the left side and dermatomes L3–S2 on the right side, and from dermatome L2 downwards along the left side, pallanaesthesia of the lower extremities and ataxia. An MRI image of the spine revealed gadolinium enhancement at the C1 and C3-5 spinal cord levels. He was diagnosed with acute transverse myelitis (Figure 2). The CSF showed 8 leukocytes/µL and an elevated protein level (72 mg/dL). Extensive microbacterial and virological studies were negative. Tumour cells were also undetectable. Immunosuppressive therapy with methylprednisolone (1 g i.v.) was administered daily for 5 consecutive days. Four days later, symptoms improved. Corticosteroids were tapered during the following 4 weeks. The follow-up examinations revealed residual hypoesthesia and paraesthesia, and slightly reduced strength of the left hand and vivid reflexes. In terms of tumour growth, the patient had a complete response to ipilimumab and remains without a relapse 4 years later.
Cases #4 and #5: Brachial plexus neuritis
Two patients with malignant melanoma were neurologically asymptomatic when nivolumab and ipilimumab, respectively, were administered. The first patient (Case #4), a 51-year-old woman, developed autoimmune hepatitis, autoimmune colitis and thromboembolic incidents after receiving a combined therapy with nivolumab (1 mg/kg) and ipilimumab (3 mg/kg). After symptoms resolved, the therapy regimen continued with biweekly nivolumab monotherapy (3 mg/kg).
After 11 months following the 20th infusion of nivolumab (3 mg/kg), she experienced massive pain in the left shoulder and neck area, which spread to the left arm. She presented to the neurology department after developing severe proximal and moderate distal weakness of the extremities. Pain was rated as 8–9 of 10 on a numeric rating scale. The left brachioradialis reflex was reduced. Electrophysiological studies conducted 5 days after symptom onset revealed no signs of chronic nerve damage in keeping with acute idiopathic plexus neuritis. The CSF had mild pleocytosis (5 leukocytes/µL) with a normal protein level. Viral and bacterial pathogens and tumour cells were undetectable. Paresis rapidly responded within 3 days of intravenous methylprednisolone (1 g/day). No symptoms recurred with continued ICI therapy.
The second patient (Case #5), a 27-year-old woman, received ipilimumab and nivolumab simultaneously or nivolumab as monotherapy in a randomized double-blind clinical trial. Eight months after beginning treatment, she complained of having pain in the left armpit and periaxillary area for more than 1 week when numbness, paraesthesia of the fourth and fifth finger along with mildly reduced strength in flexion and spreading of fingers of the left hand occurred. The left brachioradialis reflex was reduced; therefore, brachial plexus neuritis was diagnosed. The patient refused lumbar puncture and intravenous corticoids. However, the patient responded rapidly to oral steroids (100 mg prednisolone for 3 days and tapering over 8 weeks) and showed normal function of the left extremity within several days of treatment.
Both patients continued ICI treatment 3 weeks after the onset of complaints. The neuritis did not recur.
Case #6: Ocular myasthenia gravis
A 56-year-old man was diagnosed with thyroid cancer and pulmonary metastases. He was treated with pembrolizumab off-label after tumour progression, after previously undergoing radioiodine treatment, and levatinib and sorafenib therapy. Within 36 hours following the second pembrolizumab infusion and 3.5 weeks after initiating treatment, the patient developed diplopia, which worsened within 1 day. Ten days later, he had right sided ptosis, which caused near-complete eye closure. Over several days, he also developed incomplete ptosis on the left side. Dysarthria, dysphagia, or weakness of the extremities was absent. When he presented to our department, his Quantitative Myasthenia Gravis score was 10 points (of 39 points), which indicated ICI-induced myasthenia gravis (MG). Autoantibodies against neuromuscular junction proteins were negative. Repetitive nerve stimulation of the left facial nerve showed no decrement. His symptoms rapidly improved with prednisone (1 mg/kg/day), followed by slow tapering and symptomatic cholinesterase inhibitor therapy (pyridostigminbromide, 180 mg/day). During the following 6 weeks, no indication of recurrence or generalization of MG occurred. Therefore, pembrolizumab therapy was continued.
Table 1 Patients’ characteristics and the clinical findings of neurological irAEs associated with ICI therapy
|
Case 1
|
Case 2
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Case 3
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Case 4
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Case 5
|
Case 6
|
Age
|
40
|
72
|
55
|
51
|
27
|
56
|
Sex
|
Female
|
Male
|
Male
|
Female
|
Female
|
Male
|
Tumor
|
Metastatic melanoma (MM)
|
MM
|
MM
|
MM
|
MM
|
Differentiated thyroid cancer
|
Checkpoint
Inhibitor
|
Nivolumab +Ipilimumab vs.
Nivolumab
|
Nivolumab +Ipilimumab vs.
Nivolumab,
Ipilimumab +
Nivolumab
|
Ipilimumab
|
Ipilimumab +
Nivolumab,
followed by Nivolumab monotherapy
|
Nivolumab +Ipilimumab vs.
Nivolumab
|
Pembrolizumab
|
Time of initiation to symptoms
|
2 months
|
1,5 months
|
2 months
|
11 months
|
8 months
|
3,5 weeks
|
Clinical features
|
Frontal localized, pressing headache, fatigue
|
Bilateral facial nerve paralysis, reduced tendon reflexes, positive Romberg sign, mild dysmetria of upper extremities
|
Hypoesthesia lower extremities, paresis,
exaggerated tendon
reflexes, clonus
|
Pain and weakness of left arm, reduced tendon reflexes
|
Periaxillary pain and weakness of left hand, hypoesthesia reduced reflexes
|
Diplopia, bilateral ptosis
|
Diagnosis
|
Neck pain and headache attributed to hypophysitis
|
Guillain-Barré syndrome
|
Transverse Myelitis
|
Brachial plexus neuritis
|
Brachial plexus neuritis
|
Ocular myasthenia gravis
|
Diagnostics
|
Cortisol, ACTH, TSH, fT3, fT4, IGF-1, LH, FHS, estradiol; cranial MRI
|
CSF with pleocytosis, protein level of 98mg/dl, demyelinating polyneuropathy
|
CSF with mild pleocytosis,
contrast enhancement C1 and C3-5 in spinal MRI
|
CSF with mild pleocytosis
|
denied
|
Myasthenia gravis-associated antibodies negative, decrement not detectable
|
Treatment
|
100mg prednisolone i.v. bolus + hydrocortisone substitution
|
1g methylprednisolone i.v. for 3d + IVIG (0,4 g/kg/d for 5 d)
|
1g methylprednisolone i.v. for 5d + taper over 4 weeks
|
1g methylprednisolone i.v. for 3d
|
100mg prednisolone p.o. + taper over 8 weeks
|
prednisolone 1mg/kg/d p.o. + taper over 6 weeks + pyridostigmin
|
Oncological outcome
|
Progression of
metastases
|
Progression of
metastases
|
Complete remission
|
Stable tumor and pulmonary metastasis
|
Stable
|
Stable
|
Neurological
outcome
|
Complete
|
Partially resolved with sequelae
|
Excellent, mild residual Hypoesthesia, vivid reflexes
|
Complete
|
Complete
|
Excellent, mild residual ptosis on one side
|
Follow-up period
|
16 months
|
1 month
|
4 years
|
15 months
|
12 months
|
5 months
|