Intrathecal methylprednisolone for intractable postherpetic neuralgia.

Postherpetic neuralgia (PHN) is a neuropathic pain disorder that affects mostly
the elderly and which is often refractory to currently available treatments.
Many patients suffer severe physical and social disabilities as a consequence
of their chronic pain. One randomized controlled trial was published in which
intrathecal administration of methylprednisolone proved to be an effective and
safe treatment for intractable PHN. However, because of potential side effects
and lack of replication of the trial this treatment is not generally accepted.
Additional data are required to validate these promising results.
Pharmacokinetic data of intrathecal administered methylprednisolone are
lacking.

To measure the effectiveness of intrathecal methylprednisolone and lidocaine on
reducing postherpetic neuralgia.
Measurement of intrathecal methylprednisolone concentrations.

This is a monocenter, randomised, double-blind controlled trial with a 2 year
follow-up period.

For 4 weeks (the prestudy period) patients are treated with paracetamol and
NSAIDs. During this period (and afterward) concomitant PHN medication
maintained on a stable dose is allowed. After this period study drugs are
injected into the lumbar intrathecal space once a week for 4 subsequent weeks.
The index group will receive intrathecal injections with 60 milligram
methylprednisolone and 60 mg lidocaine, the placebo group will receive 60
milligrams of lidocaine. The potentially neurotoxic preservatives are removed
from the methylprednisolone. Before the each injection and 1,4 and 8 weeks
after the last injection samples of cerebrospinal fluid are obtained for
methylprednisolone concentration testing. Pain is evaluated at randomisation,
before the first spinal injection, before the fourth injection and then 4
weeks, 8 weeks, 6 months, 1 year and 2 years after the end of treatment. The
EQ5D questionnaire will be used to evaluate the subject*s perception of the
general quality of life.

We are planning to offer this new treatment to this group of patients who have
no other treatment options. We prefer to do so in a research setting for above
mentioned reasons (see section E9a). The burden for the patient will be 3
additional intrathecal puncions for obtaining cerebrospinal fluid.
Spinal anesthesia is a routine procedure that is used millions of times each
year. It is safe and rarely associated with neurologic complications [1].

[1] Horlocker et al. A retrospective review of 4767 consecutive spinal
anesthetics: central nervous system complications. Anesth Analg 1997; 84: p.
578-84.

[2] Santanen et al. Comparison of 27-gauge Whitacre and Quincke spinal needles
with respect to post-dural puncture headache and nondural pncture headachte.
Acta anaesthesiol scand 2004;48:474-479.